Snowpack

Cryosphere

This indicator measures trends in the amount and timing of snowpack in the western United States.

Figures

Figure 1. Trends in April Snowpack in the Western United States, 1955-2023

Data source: USDA Natural Resources Conservation Service, 2024⁵
Web update: June 2024

This map shows trends in April snowpack in the western United States, measured in terms of snow water equivalent. Blue circles represent increased snowpack; red circles represent a decrease.

Show the data behind this figure

State	Latitude	Longitude	Value	Unit
OR	45.19107°N	118.55015°W	-99.96	percent change
NV	41.96737°N	118.18934°W	-89.82	percent change
NV	41.51542°N	117.63197°W	-79.20	percent change
MT	46.86945°N	113.45938°W	-78.74	percent change
OR	42.12587°N	120.83610°W	-78.12	percent change
OR	45.27478°N	118.84790°W	-77.42	percent change
OR	45.36428°N	118.46715°W	-76.60	percent change
WA	48.57815°N	121.02510°W	-74.95	percent change
MT	48.17478°N	109.64728°W	-73.75	percent change
OR	44.43503°N	121.94502°W	-73.01	percent change
WA	47.31660°N	121.51660°W	-71.38	percent change
NV	41.78333°N	119.61667°W	-69.12	percent change
ID	48.35095°N	116.83633°W	-68.34	percent change
MT	48.30305°N	113.32868°W	-66.20	percent change
ID	43.57033°N	113.91257°W	-64.56	percent change
CA	40.28300°N	121.25000°W	-64.22	percent change
NM	36.13333°N	105.53333°W	-63.74	percent change
OR	43.18787°N	122.14003°W	-62.27	percent change
UT	40.98492°N	110.85075°W	-61.91	percent change
OR	45.55808°N	118.45383°W	-60.26	percent change
CA	41.07700°N	122.93800°W	-59.04	percent change
WA	47.97078°N	123.49987°W	-58.76	percent change
NV	39.10988°N	119.88797°W	-58.13	percent change
OR	44.42042°N	121.85655°W	-57.92	percent change
MT	46.86552°N	113.41537°W	-57.71	percent change
UT	39.13683°N	111.55813°W	-57.02	percent change
OR	43.22625°N	121.80662°W	-56.94	percent change
OR	43.30583°N	122.15932°W	-56.84	percent change
WA	48.53439°N	119.86241°W	-55.91	percent change
OR	44.59397°N	121.97365°W	-55.25	percent change
NV	41.53333°N	116.03333°W	-54.65	percent change
OR	44.21007°N	118.63752°W	-53.97	percent change
CA	41.40000°N	123.00100°W	-53.27	percent change
CA	41.39700°N	122.99300°W	-52.62	percent change
MT	47.57695°N	113.31283°W	-52.51	percent change
MT	46.43380°N	113.06208°W	-52.27	percent change
ID	44.28846°N	115.65508°W	-52.07	percent change
OR	44.76380°N	118.31170°W	-50.47	percent change
MT	47.91328°N	112.92473°W	-50.39	percent change
MT	47.70255°N	112.88097°W	-49.90	percent change
CA	40.29300°N	121.29200°W	-49.54	percent change
CA	41.19700°N	122.52300°W	-48.91	percent change
OR	44.65567°N	118.42617°W	-48.54	percent change
UT	37.51255°N	113.39661°W	-48.52	percent change
OR	44.38605°N	122.16683°W	-48.33	percent change
ID	42.26015°N	112.12515°W	-47.92	percent change
MT	45.92242°N	113.72588°W	-47.88	percent change
ID	43.61040°N	113.93080°W	-47.68	percent change
OR	42.75333°N	118.68785°W	-47.46	percent change
MT	46.21380°N	113.28330°W	-46.99	percent change
WA	47.32004°N	121.33869°W	-46.61	percent change
CO	37.81667°N	107.11667°W	-46.55	percent change
WA	47.35037°N	120.67960°W	-46.48	percent change
WA	47.94842°N	123.25858°W	-46.40	percent change
NM	35.83333°N	105.66667°W	-45.75	percent change
WY	44.36888°N	110.57825°W	-45.73	percent change
CA	41.04500°N	122.47800°W	-45.51	percent change
CO	37.65083°N	107.80602°W	-45.22	percent change
OR	42.43933°N	122.22880°W	-45.18	percent change
NV	41.04393°N	115.09555°W	-45.17	percent change
UT	39.92976°N	111.63109°W	-44.94	percent change
NV	41.75093°N	115.67798°W	-44.93	percent change
OR	44.83052°N	118.18787°W	-44.73	percent change
CO	37.38333°N	106.40000°W	-43.82	percent change
ID	43.48407°N	114.82692°W	-43.81	percent change
WY	44.91667°N	110.61667°W	-43.68	percent change
OR	44.44650°N	119.93012°W	-43.64	percent change
OR	44.14425°N	121.64095°W	-43.28	percent change
OR	45.04148°N	121.93252°W	-42.89	percent change
ID	44.43700°N	111.99384°W	-42.27	percent change
MT	47.87257°N	112.93057°W	-41.66	percent change
CO	40.61667°N	105.83333°W	-41.52	percent change
OR	44.86887°N	118.11387°W	-41.40	percent change
CA	38.88285°N	119.97765°W	-40.66	percent change
MT	48.75663°N	113.82025°W	-40.58	percent change
OR	42.38010°N	122.34943°W	-39.50	percent change
CA	39.49001°N	120.28226°W	-39.39	percent change
ID	47.45749°N	115.70457°W	-39.36	percent change
MT	44.58907°N	111.82498°W	-38.80	percent change
MT	44.59320°N	111.81680°W	-38.51	percent change
CO	37.85000°N	107.16667°W	-38.15	percent change
ID	45.07220°N	116.45413°W	-38.05	percent change
MT	44.87189°N	111.34391°W	-37.87	percent change
OR	44.51365°N	123.55597°W	-37.74	percent change
CA	41.17000°N	121.93800°W	-37.58	percent change
MT	47.96252°N	115.53938°W	-37.50	percent change
OR	43.51185°N	121.97982°W	-37.47	percent change
CA	39.72500°N	122.85000°W	-36.99	percent change
WY	42.80833°N	110.89528°W	-36.80	percent change
MT	48.00957°N	112.82405°W	-36.75	percent change
NV	41.57872°N	115.93182°W	-36.40	percent change
OR	43.98513°N	121.53868°W	-36.26	percent change
NV	41.76168°N	115.69310°W	-35.97	percent change
WY	44.36917°N	110.57717°W	-35.69	percent change
CO	37.37929°N	106.54835°W	-35.59	percent change
CA	41.80800°N	122.19500°W	-35.56	percent change
MT	46.89898°N	113.45325°W	-35.48	percent change
CA	39.14200°N	120.22500°W	-35.48	percent change
WY	44.75000°N	110.70000°W	-35.46	percent change
MT	48.37007°N	114.86688°W	-35.23	percent change
CO	40.03333°N	107.28333°W	-35.05	percent change
CA	41.00800°N	122.80000°W	-34.89	percent change
MT	47.33178°N	113.58210°W	-34.83	percent change
CO	37.80000°N	106.80000°W	-34.70	percent change
UT	41.92200°N	111.46817°W	-34.64	percent change
WY	43.27676°N	109.44585°W	-34.63	percent change
CA	41.09300°N	122.48300°W	-34.32	percent change
CA	40.50000°N	121.15000°W	-34.21	percent change
OR	45.62237°N	121.70415°W	-34.20	percent change
WA	47.53565°N	121.08553°W	-34.19	percent change
OR	42.69570°N	120.80158°W	-34.15	percent change
UT	38.50809°N	112.01856°W	-34.14	percent change
CO	39.87505°N	107.59853°W	-34.07	percent change
CO	40.40000°N	105.65000°W	-34.06	percent change
UT	40.16483°N	111.20665°W	-33.85	percent change
OR	42.40717°N	122.26617°W	-33.75	percent change
CO	39.06667°N	106.61667°W	-33.67	percent change
WA	48.65518°N	119.83830°W	-33.44	percent change
ID	42.16442°N	114.19272°W	-33.07	percent change
UT	39.45197°N	111.27221°W	-33.02	percent change
WY	43.13097°N	110.20230°W	-33.00	percent change
WA	47.27427°N	121.34162°W	-32.98	percent change
CA	39.31700°N	120.64200°W	-32.89	percent change
ID	44.05092°N	115.44322°W	-32.85	percent change
NM	36.41168°N	105.33345°W	-32.52	percent change
ID	43.82432°N	114.26402°W	-32.33	percent change
CA	39.84200°N	122.95000°W	-32.26	percent change
WY	43.54056°N	109.74722°W	-32.21	percent change
ID	45.15000°N	116.00000°W	-32.15	percent change
ID	44.92075°N	115.95108°W	-32.14	percent change
CO	40.28333°N	105.76667°W	-32.10	percent change
CA	41.36700°N	122.55000°W	-32.07	percent change
NV	38.97485°N	114.25147°W	-31.91	percent change
CA	38.82800°N	120.03700°W	-31.87	percent change
MT	48.32600°N	114.64365°W	-31.74	percent change
MT	46.11192°N	110.46960°W	-31.71	percent change
CA	39.90000°N	121.25700°W	-31.68	percent change
CA	41.15000°N	122.45000°W	-31.62	percent change
CA	39.28200°N	120.52700°W	-31.53	percent change
ID	42.52497°N	111.95635°W	-31.29	percent change
WA	48.19273°N	117.43277°W	-31.07	percent change
ID	42.56248°N	111.29797°W	-30.99	percent change
ID	43.93200°N	115.66588°W	-30.97	percent change
CO	37.69866°N	107.77715°W	-30.90	percent change
WA	48.94862°N	120.93280°W	-30.73	percent change
MT	48.57120°N	115.44573°W	-30.66	percent change
ID	46.56603°N	115.74216°W	-30.55	percent change
WY	43.38939°N	110.12943°W	-30.45	percent change
MT	48.31967°N	113.35833°W	-30.41	percent change
CO	40.41667°N	105.81667°W	-30.39	percent change
OR	42.95615°N	121.18123°W	-30.36	percent change
ID	44.54514°N	115.56380°W	-30.31	percent change
ID	42.36055°N	111.56085°W	-30.31	percent change
CO	40.07806°N	106.67028°W	-30.21	percent change
MT	48.41322°N	113.95497°W	-30.09	percent change
WY	44.18333°N	107.25000°W	-30.00	percent change
WA	48.87926°N	121.25529°W	-29.86	percent change
UT	41.41289°N	111.53770°W	-29.84	percent change
WY	44.34847°N	107.01360°W	-29.83	percent change
MT	47.91568°N	113.47413°W	-29.77	percent change
UT	39.32067°N	111.48790°W	-29.76	percent change
ID	43.74367°N	113.93797°W	-29.72	percent change
ID	44.44310°N	112.22758°W	-29.70	percent change
OR	43.24508°N	122.29320°W	-29.67	percent change
ID	42.31023°N	111.66895°W	-29.56	percent change
WY	43.57500°N	109.80139°W	-29.03	percent change
CA	41.31800°N	122.50300°W	-28.95	percent change
MT	45.56311°N	110.92929°W	-28.85	percent change
CA	39.45269°N	120.29367°W	-28.81	percent change
MT	45.84997°N	112.45567°W	-28.80	percent change
ID	44.95222°N	116.14293°W	-28.72	percent change
MT	48.43412°N	113.93725°W	-28.46	percent change
NM	35.80000°N	105.80000°W	-28.31	percent change
CA	39.85700°N	121.26300°W	-28.27	percent change
SD	44.20000°N	104.00000°W	-28.18	percent change
WY	42.96400°N	110.60973°W	-27.98	percent change
CA	39.76200°N	120.71300°W	-27.97	percent change
UT	38.48323°N	109.28960°W	-27.96	percent change
MT	46.83952°N	110.69207°W	-27.78	percent change
WA	48.52400°N	120.98900°W	-27.72	percent change
CA	39.94200°N	121.19000°W	-27.54	percent change
CO	40.40000°N	106.60000°W	-27.38	percent change
MT	44.92004°N	111.05468°W	-27.36	percent change
MT	46.58515°N	113.57242°W	-27.29	percent change
NV	39.25305°N	119.87717°W	-27.22	percent change
MT	48.49633°N	114.35613°W	-27.20	percent change
UT	40.18505°N	111.35937°W	-27.17	percent change
CA	39.72500°N	120.93200°W	-27.00	percent change
OR	44.24767°N	118.51722°W	-26.97	percent change
OR	45.21328°N	117.19258°W	-26.94	percent change
WA	48.51865°N	120.73580°W	-26.90	percent change
WY	43.24930°N	110.01662°W	-26.80	percent change
ID	44.64602°N	111.31183°W	-26.76	percent change
ID	43.87722°N	114.67250°W	-26.63	percent change
WY	42.56083°N	108.82972°W	-26.47	percent change
CA	40.48200°N	121.00700°W	-26.25	percent change
ID	43.81530°N	113.91717°W	-26.24	percent change
OR	44.21030°N	121.87292°W	-26.14	percent change
CO	40.20000°N	105.60000°W	-26.01	percent change
ID	44.62621°N	115.79561°W	-25.94	percent change
ID	44.48275°N	111.27465°W	-25.82	percent change
WY	41.18333°N	106.16667°W	-25.81	percent change
CA	38.92025°N	120.03953°W	-25.77	percent change
ID	44.40057°N	111.89473°W	-25.48	percent change
CA	40.38700°N	121.31000°W	-25.35	percent change
CA	37.45000°N	118.74200°W	-25.31	percent change
MT	44.65866°N	111.09199°W	-25.17	percent change
AZ	34.00000°N	109.51667°W	-25.16	percent change
CA	40.76200°N	121.19500°W	-25.10	percent change
WY	42.30023°N	110.67753°W	-25.10	percent change
CA	41.21700°N	122.80700°W	-25.08	percent change
WY	44.47825°N	110.03808°W	-25.04	percent change
WA	47.37406°N	121.44213°W	-24.96	percent change
CA	40.96700°N	122.86700°W	-24.80	percent change
CA	41.35300°N	122.24700°W	-24.76	percent change
CO	40.03523°N	105.54426°W	-24.64	percent change
WY	42.35967°N	110.76870°W	-24.63	percent change
WY	43.82028°N	110.26862°W	-24.60	percent change
CA	40.41800°N	121.27500°W	-24.58	percent change
CO	40.22543°N	105.91977°W	-24.56	percent change
OR	42.87007°N	122.16518°W	-24.55	percent change
UT	40.63300°N	111.63300°W	-24.54	percent change
WY	44.26778°N	110.62612°W	-24.44	percent change
WY	44.13352°N	110.66900°W	-24.32	percent change
ID	43.62903°N	115.43818°W	-24.21	percent change
MT	47.27260°N	113.75617°W	-24.18	percent change
MT	46.89093°N	112.49857°W	-24.03	percent change
CA	40.35500°N	121.42200°W	-24.00	percent change
WY	41.32943°N	106.50248°W	-23.98	percent change
UT	40.29530°N	111.25677°W	-23.94	percent change
UT	40.67450°N	111.21798°W	-23.81	percent change
CA	39.97300°N	121.21300°W	-23.81	percent change
WY	41.33333°N	106.20000°W	-23.74	percent change
CO	37.98333°N	107.25000°W	-23.73	percent change
UT	39.31042°N	111.43297°W	-23.72	percent change
ID	42.76478°N	116.90037°W	-23.67	percent change
MT	48.95832°N	114.42037°W	-23.64	percent change
CA	41.58245°N	120.30202°W	-23.51	percent change
ID	43.76850°N	114.41812°W	-23.51	percent change
MT	45.21665°N	113.50143°W	-23.46	percent change
CA	37.43800°N	118.77300°W	-23.44	percent change
CA	41.21700°N	122.41700°W	-23.43	percent change
ID	43.79942°N	114.85273°W	-23.42	percent change
CA	41.43500°N	122.10000°W	-23.24	percent change
MT	46.43643°N	112.29167°W	-23.12	percent change
NV	39.08438°N	119.90348°W	-23.08	percent change
CO	37.35000°N	106.55000°W	-22.98	percent change
UT	40.79669°N	110.88472°W	-22.79	percent change
WY	42.52516°N	110.66148°W	-22.72	percent change
ID	48.05726°N	116.23055°W	-22.53	percent change
MT	46.24212°N	113.77250°W	-22.27	percent change
CO	39.51667°N	105.71667°W	-22.26	percent change
OR	44.42917°N	120.33110°W	-22.24	percent change
UT	38.78903°N	111.68870°W	-22.04	percent change
ID	43.54248°N	111.04602°W	-22.01	percent change
CA	41.02300°N	122.88500°W	-21.92	percent change
WA	47.53469°N	121.08592°W	-21.85	percent change
MT	48.95642°N	114.75603°W	-21.85	percent change
CA	40.71000°N	121.57700°W	-21.67	percent change
WY	44.13361°N	110.66917°W	-21.59	percent change
MT	48.90922°N	115.35612°W	-21.57	percent change
CO	40.51667°N	105.56667°W	-21.53	percent change
WY	44.12612°N	110.83435°W	-21.49	percent change
CA	39.31000°N	120.33800°W	-21.48	percent change
UT	40.42817°N	111.61633°W	-21.34	percent change
CA	39.68200°N	120.62300°W	-21.28	percent change
CA	41.23583°N	120.79192°W	-21.25	percent change
WY	44.12612°N	110.83435°W	-21.20	percent change
WY	44.20862°N	110.66628°W	-21.16	percent change
NV	40.38480°N	115.52757°W	-21.07	percent change
UT	38.50515°N	111.76745°W	-20.92	percent change
WY	43.85722°N	110.58445°W	-20.92	percent change
CA	41.20000°N	122.83300°W	-20.89	percent change
NV	40.64480°N	115.38120°W	-20.78	percent change
MT	47.27260°N	113.75617°W	-20.78	percent change
WY	44.04572°N	110.68950°W	-20.76	percent change
ID	42.05050°N	111.60120°W	-20.50	percent change
UT	39.96450°N	110.98845°W	-20.50	percent change
MT	45.40125°N	110.95758°W	-20.48	percent change
WA	48.51729°N	120.73517°W	-20.41	percent change
MT	47.46182°N	113.52312°W	-20.36	percent change
ID	43.66223°N	114.40523°W	-20.35	percent change
UT	39.61153°N	111.30493°W	-20.33	percent change
ID	42.38005°N	112.96432°W	-20.32	percent change
CO	40.03279°N	105.57615°W	-20.19	percent change
CO	40.40000°N	105.83333°W	-20.16	percent change
UT	40.76184°N	111.62917°W	-20.04	percent change
CO	40.80000°N	105.76667°W	-20.01	percent change
OR	43.80368°N	121.94793°W	-19.96	percent change
CA	37.66700°N	119.62500°W	-19.94	percent change
CA	37.12700°N	118.47000°W	-19.76	percent change
UT	37.48997°N	112.57602°W	-19.76	percent change
OR	42.92545°N	122.39723°W	-19.64	percent change
UT	40.71632°N	109.54401°W	-19.62	percent change
CA	38.67800°N	120.11800°W	-19.61	percent change
ID	46.32668°N	115.06915°W	-19.57	percent change
WY	42.49490°N	110.53203°W	-19.47	percent change
ID	43.75690°N	115.23907°W	-19.46	percent change
CA	41.58700°N	121.61300°W	-19.16	percent change
WA	48.72047°N	120.65860°W	-19.04	percent change
ID	43.93206°N	115.66515°W	-18.98	percent change
WA	48.19798°N	120.91678°W	-18.90	percent change
CA	38.86755°N	119.95652°W	-18.87	percent change
CO	38.16667°N	106.60000°W	-18.65	percent change
ID	44.30342°N	115.23447°W	-18.49	percent change
WY	41.35885°N	106.23209°W	-18.49	percent change
CA	37.76500°N	119.77300°W	-18.45	percent change
WY	43.17387°N	110.14007°W	-18.45	percent change
UT	37.57500°N	112.90155°W	-18.32	percent change
CA	39.35300°N	120.35300°W	-18.21	percent change
ID	45.67008°N	113.95315°W	-18.17	percent change
MT	46.52557°N	110.77242°W	-18.11	percent change
WY	44.53778°N	107.50111°W	-18.05	percent change
CA	41.37200°N	122.23000°W	-18.02	percent change
UT	39.30190°N	111.45277°W	-18.01	percent change
OR	44.44722°N	119.93062°W	-17.85	percent change
CA	38.10200°N	119.74500°W	-17.85	percent change
OR	42.05257°N	122.85487°W	-17.84	percent change
ID	43.86117°N	114.20902°W	-17.83	percent change
CA	38.54300°N	120.37700°W	-17.71	percent change
UT	41.46547°N	111.49688°W	-17.68	percent change
OR	43.90098°N	122.03063°W	-17.68	percent change
ID	42.14013°N	111.62592°W	-17.67	percent change
MT	45.00565°N	110.01406°W	-17.66	percent change
CO	39.88837°N	105.89031°W	-17.56	percent change
CA	41.30500°N	122.49300°W	-17.56	percent change
CA	38.09200°N	119.75800°W	-17.46	percent change
WY	43.74902°N	110.05780°W	-17.45	percent change
CA	38.81800°N	120.07200°W	-17.41	percent change
UT	40.86493°N	110.79813°W	-17.38	percent change
WY	43.63083°N	109.92250°W	-17.38	percent change
WY	44.21194°N	106.99722°W	-17.30	percent change
CO	39.63333°N	105.90000°W	-17.25	percent change
UT	41.88467°N	111.56882°W	-17.22	percent change
CA	40.01667°N	120.30000°W	-17.11	percent change
CA	38.03300°N	119.87800°W	-17.05	percent change
NV	41.83384°N	115.45278°W	-17.00	percent change
UT	40.78931°N	111.09192°W	-16.95	percent change
WY	41.31667°N	106.50000°W	-16.93	percent change
WA	48.72138°N	120.66135°W	-16.79	percent change
MT	47.94622°N	113.75248°W	-16.77	percent change
OR	45.42870°N	121.85605°W	-16.75	percent change
ID	44.81500°N	116.69278°W	-16.68	percent change
WY	44.20862°N	110.66628°W	-16.66	percent change
CO	40.36783°N	106.74038°W	-16.63	percent change
CA	38.08500°N	119.83700°W	-16.58	percent change
CA	39.18118°N	120.25030°W	-16.41	percent change
MT	46.09713°N	113.13038°W	-16.30	percent change
CA	39.36000°N	120.50000°W	-16.28	percent change
CO	38.81667°N	106.58333°W	-16.27	percent change
UT	37.63385°N	112.16947°W	-16.26	percent change
WY	42.64694°N	108.86889°W	-16.24	percent change
UT	40.59936°N	111.58167°W	-16.21	percent change
CA	37.27700°N	118.96200°W	-16.18	percent change
UT	40.67800°N	110.94873°W	-16.13	percent change
CO	40.36667°N	106.10000°W	-16.09	percent change
OR	43.59042°N	122.06010°W	-15.95	percent change
MT	46.08835°N	113.26810°W	-15.93	percent change
ID	43.91358°N	116.01330°W	-15.92	percent change
CA	38.69300°N	119.99800°W	-15.81	percent change
NV	38.97098°N	114.27697°W	-15.71	percent change
WA	48.74869°N	120.86084°W	-15.65	percent change
CA	38.99927°N	120.13139°W	-15.58	percent change
CA	37.99500°N	119.78000°W	-15.54	percent change
MT	45.73107°N	114.48075°W	-15.42	percent change
MT	45.47072°N	113.09773°W	-15.15	percent change
ID	45.04315°N	116.13253°W	-15.10	percent change
UT	41.89833°N	111.62957°W	-15.08	percent change
ID	48.35490°N	116.76855°W	-14.99	percent change
CO	39.30000°N	106.60000°W	-14.99	percent change
CA	39.75500°N	120.72000°W	-14.95	percent change
WY	43.34298°N	110.43495°W	-14.64	percent change
CO	37.48333°N	106.83333°W	-14.62	percent change
WY	43.71417°N	109.63667°W	-14.55	percent change
ID	46.46633°N	114.63333°W	-14.51	percent change
CO	39.07539°N	106.61169°W	-14.49	percent change
WY	43.94583°N	110.44677°W	-14.46	percent change
CO	40.87502°N	106.04603°W	-14.46	percent change
CO	40.41432°N	105.81980°W	-14.45	percent change
CA	36.12200°N	118.54500°W	-14.45	percent change
UT	38.88185°N	112.24915°W	-14.40	percent change
CA	38.82000°N	120.03700°W	-14.38	percent change
ID	42.75743°N	112.47783°W	-14.29	percent change
UT	39.68338°N	111.31818°W	-14.28	percent change
CO	37.74932°N	107.68866°W	-14.23	percent change
OR	44.56953°N	117.84250°W	-14.21	percent change
UT	41.68541°N	111.41987°W	-14.15	percent change
CO	40.53397°N	106.78130°W	-14.14	percent change
UT	39.13667°N	111.50542°W	-13.99	percent change
UT	37.86943°N	109.44717°W	-13.75	percent change
UT	37.74797°N	112.77495°W	-13.72	percent change
CA	37.40800°N	119.48000°W	-13.69	percent change
CO	40.84781°N	106.96871°W	-13.68	percent change
CA	39.35500°N	120.50300°W	-13.65	percent change
WA	48.44488°N	120.91551°W	-13.57	percent change
NV	41.22870°N	116.02930°W	-13.55	percent change
OR	43.44907°N	122.13808°W	-13.50	percent change
UT	40.67933°N	110.94877°W	-13.40	percent change
CA	41.23483°N	120.79467°W	-13.39	percent change
WA	46.78265°N	121.74765°W	-13.39	percent change
CA	41.38200°N	122.53500°W	-13.37	percent change
UT	38.20840°N	111.47412°W	-13.19	percent change
NV	40.89343°N	115.21104°W	-13.15	percent change
UT	40.44293°N	112.22377°W	-13.13	percent change
CA	38.01700°N	119.71700°W	-13.11	percent change
UT	39.86671°N	111.28363°W	-13.08	percent change
WY	43.85805°N	110.27667°W	-12.94	percent change
WY	41.08333°N	106.16667°W	-12.77	percent change
CO	38.48333°N	106.33333°W	-12.59	percent change
ID	44.42030°N	111.38512°W	-12.46	percent change
CO	39.78333°N	105.78333°W	-12.36	percent change
CO	40.01667°N	105.56667°W	-12.24	percent change
CA	39.30300°N	120.54300°W	-12.23	percent change
ID	42.76740°N	112.10648°W	-12.16	percent change
CA	38.60800°N	119.92437°W	-12.15	percent change
CO	40.39480°N	106.60408°W	-12.15	percent change
CO	40.36667°N	106.76667°W	-12.00	percent change
WY	42.50750°N	110.90990°W	-11.98	percent change
CO	39.29722°N	106.60694°W	-11.95	percent change
WY	44.78765°N	107.52917°W	-11.84	percent change
CA	36.57000°N	118.76800°W	-11.76	percent change
UT	39.89275°N	111.25154°W	-11.70	percent change
CO	39.07813°N	107.14389°W	-11.68	percent change
NV	40.27551°N	115.54017°W	-11.58	percent change
ID	43.60250°N	114.67417°W	-11.45	percent change
WA	48.81822°N	121.19144°W	-11.27	percent change
CA	41.22500°N	122.81100°W	-11.24	percent change
CA	37.12800°N	118.47500°W	-11.11	percent change
UT	38.48383°N	112.39273°W	-10.92	percent change
UT	40.85464°N	111.04765°W	-10.83	percent change
CO	37.93333°N	107.80000°W	-10.81	percent change
CA	39.48300°N	120.44000°W	-10.74	percent change
UT	38.67990°N	111.59765°W	-10.73	percent change
MT	45.16507°N	113.50099°W	-10.73	percent change
WY	42.57317°N	108.84325°W	-10.57	percent change
WY	43.74902°N	110.05780°W	-10.50	percent change
OR	45.14532°N	118.21900°W	-10.45	percent change
UT	39.89166°N	110.74604°W	-10.44	percent change
CA	41.58233°N	120.30250°W	-10.35	percent change
ID	42.95275°N	111.35933°W	-10.27	percent change
WY	41.15397°N	106.96937°W	-10.12	percent change
CO	37.48576°N	106.83535°W	-10.11	percent change
CA	38.15800°N	119.66200°W	-9.99	percent change
CA	36.24300°N	118.67800°W	-9.99	percent change
WY	43.50278°N	109.75200°W	-9.85	percent change
OR	43.61193°N	122.11758°W	-9.82	percent change
CO	38.51667°N	106.33333°W	-9.72	percent change
NV	36.27325°N	115.67467°W	-9.50	percent change
CO	37.96667°N	107.66667°W	-9.31	percent change
CA	38.85190°N	119.93740°W	-9.21	percent change
OR	44.43338°N	120.33583°W	-9.15	percent change
OR	42.89988°N	122.13642°W	-8.89	percent change
CO	40.78333°N	105.93333°W	-8.88	percent change
WY	44.71961°N	110.51084°W	-8.77	percent change
WY	43.65868°N	109.00988°W	-8.65	percent change
CO	40.20000°N	105.56667°W	-8.62	percent change
CA	37.18300°N	118.76200°W	-8.50	percent change
WA	47.01872°N	121.46464°W	-8.49	percent change
OR	45.27173°N	117.68747°W	-8.44	percent change
CO	39.08333°N	106.53333°W	-8.34	percent change
CO	38.88333°N	107.00000°W	-8.33	percent change
WY	41.31667°N	106.43333°W	-8.21	percent change
CA	37.49800°N	119.40800°W	-7.80	percent change
CA	38.85952°N	120.11362°W	-7.71	percent change
CA	38.62500°N	120.21800°W	-7.65	percent change
CA	37.75200°N	119.16200°W	-7.61	percent change
CA	38.69500°N	119.98300°W	-7.37	percent change
CA	37.02300°N	119.08000°W	-7.27	percent change
WY	42.58612°N	109.08583°W	-7.20	percent change
WY	42.52388°N	110.88305°W	-7.18	percent change
CA	40.46700°N	121.50800°W	-7.16	percent change
ID	44.47212°N	114.48992°W	-7.14	percent change
OR	45.46430°N	121.70428°W	-7.11	percent change
WY	44.09988°N	110.73683°W	-6.97	percent change
CA	38.61800°N	120.22800°W	-6.86	percent change
CO	38.81996°N	106.58974°W	-6.50	percent change
CA	38.71000°N	120.04200°W	-6.47	percent change
WA	48.68125°N	119.87224°W	-6.40	percent change
ID	42.09762°N	114.17287°W	-6.37	percent change
CA	39.43600°N	120.52500°W	-6.36	percent change
CA	37.62000°N	118.99200°W	-6.36	percent change
UT	41.37603°N	111.94405°W	-6.18	percent change
CO	40.35000°N	106.10000°W	-6.11	percent change
CA	39.41700°N	120.50800°W	-5.87	percent change
CO	37.60000°N	105.20000°W	-5.71	percent change
MT	47.68493°N	113.96230°W	-5.61	percent change
CA	37.39700°N	119.51800°W	-5.53	percent change
CA	39.34300°N	120.50800°W	-5.51	percent change
CO	40.40000°N	105.63333°W	-5.27	percent change
WY	42.86984°N	109.09455°W	-5.23	percent change
OR	42.70992°N	118.63210°W	-5.10	percent change
ID	43.76400°N	116.09700°W	-5.08	percent change
WY	41.31667°N	106.18333°W	-4.83	percent change
ID	43.87497°N	114.71363°W	-4.78	percent change
NV	40.65802°N	115.43415°W	-4.78	percent change
CO	40.81666°N	105.65000°W	-4.75	percent change
CA	37.25800°N	118.99700°W	-4.74	percent change
CA	38.80300°N	120.10300°W	-4.74	percent change
CA	37.27200°N	118.87700°W	-4.71	percent change
ID	42.18072°N	114.28662°W	-4.68	percent change
CA	38.16700°N	119.94200°W	-4.34	percent change
CA	38.04700°N	119.67000°W	-4.21	percent change
CA	38.04300°N	119.88700°W	-4.10	percent change
WY	43.94019°N	110.44544°W	-3.99	percent change
CA	38.51700°N	119.90000°W	-3.87	percent change
NM	36.66667°N	105.36667°W	-3.80	percent change
CA	37.32000°N	118.87200°W	-3.67	percent change
CA	41.40000°N	122.05000°W	-3.66	percent change
CO	39.05000°N	108.08333°W	-3.63	percent change
CA	38.50300°N	120.46700°W	-3.61	percent change
MT	44.65866°N	111.09199°W	-3.42	percent change
NV	41.66198°N	115.32397°W	-3.27	percent change
WY	43.69733°N	109.67021°W	-3.20	percent change
NV	40.60175°N	115.37683°W	-2.87	percent change
CA	35.96500°N	118.36000°W	-2.36	percent change
NV	40.86208°N	115.22078°W	-1.94	percent change
CA	37.45700°N	118.79500°W	-1.81	percent change
CO	40.26667°N	105.58333°W	-1.77	percent change
CA	38.60000°N	119.91667°W	-1.44	percent change
NV	40.32443°N	115.56217°W	-1.37	percent change
CA	39.45800°N	120.60000°W	-1.34	percent change
CA	38.24200°N	119.94200°W	-1.13	percent change
CA	36.44000°N	118.25500°W	-0.82	percent change
CA	37.20800°N	119.07300°W	-0.77	percent change
CO	38.48884°N	106.33965°W	-0.57	percent change
CA	37.38800°N	118.90300°W	-0.46	percent change
CO	40.58333°N	105.63333°W	-0.32	percent change
CA	36.43700°N	118.58700°W	-0.30	percent change
CA	37.41000°N	119.49000°W	-0.28	percent change
CA	37.17800°N	118.72000°W	-0.26	percent change
CO	39.53333°N	106.21667°W	-0.02	percent change
CA	39.00100°N	120.14000°W	0.36	percent change
NV	39.29148°N	117.11506°W	0.77	percent change
CO	39.78333°N	106.01667°W	0.80	percent change
CA	38.28800°N	119.83200°W	0.83	percent change
UT	40.54875°N	110.69292°W	1.00	percent change
CA	39.47000°N	120.57200°W	1.04	percent change
CO	39.37991°N	106.19681°W	1.30	percent change
UT	40.88529°N	111.06954°W	1.42	percent change
ID	42.36467°N	111.50605°W	1.79	percent change
CA	36.71500°N	118.84200°W	1.91	percent change
CA	37.29500°N	119.10200°W	1.98	percent change
UT	38.30183°N	112.35672°W	2.09	percent change
NV	41.87255°N	115.24713°W	2.11	percent change
CA	38.08300°N	119.63300°W	2.19	percent change
CA	37.66300°N	119.01700°W	2.20	percent change
MT	45.03665°N	110.60805°W	2.20	percent change
NV	39.30615°N	117.11898°W	2.25	percent change
CO	40.80571°N	105.76993°W	2.38	percent change
MT	46.45542°N	112.28783°W	2.48	percent change
CA	36.41500°N	118.57900°W	2.51	percent change
CA	37.10000°N	118.55700°W	2.53	percent change
CA	38.26355°N	119.45635°W	2.54	percent change
CA	36.99300°N	118.90200°W	2.66	percent change
CA	37.61000°N	119.03300°W	3.03	percent change
CA	38.81200°N	120.37500°W	3.12	percent change
NV	38.96715°N	114.28668°W	3.14	percent change
CA	37.83800°N	119.44800°W	3.28	percent change
NV	41.67032°N	117.56668°W	3.64	percent change
CA	38.18333°N	119.61667°W	3.75	percent change
CA	37.02500°N	118.90800°W	3.76	percent change
CA	36.48300°N	118.17700°W	3.78	percent change
CO	40.08333°N	106.55000°W	4.12	percent change
CA	36.52300°N	118.34800°W	4.12	percent change
WY	44.25602°N	106.97983°W	4.25	percent change
NV	39.16395°N	119.89672°W	4.40	percent change
CA	36.77000°N	118.39800°W	4.54	percent change
CO	39.36127°N	106.05978°W	4.56	percent change
CA	36.47300°N	118.26700°W	4.64	percent change
CA	40.25800°N	121.04700°W	4.76	percent change
CA	37.25700°N	119.22500°W	4.96	percent change
CO	39.83333°N	105.75000°W	5.03	percent change
CA	37.95700°N	119.26700°W	5.11	percent change
CA	37.16200°N	118.56300°W	5.23	percent change
CA	38.28000°N	119.73000°W	5.41	percent change
UT	38.77246°N	111.67662°W	5.44	percent change
CA	37.47300°N	118.71700°W	5.66	percent change
CA	38.32700°N	119.91200°W	5.79	percent change
CA	37.18400°N	118.93800°W	6.00	percent change
WY	44.55000°N	110.40000°W	6.19	percent change
CA	37.59800°N	119.26700°W	6.25	percent change
CA	35.87300°N	118.58700°W	6.27	percent change
CO	40.39937°N	105.84757°W	6.36	percent change
CA	37.06700°N	118.77000°W	6.41	percent change
CA	37.63700°N	119.55000°W	6.47	percent change
CA	37.52800°N	119.27500°W	6.62	percent change
CA	36.77000°N	118.41500°W	6.69	percent change
CA	36.58800°N	118.71700°W	6.89	percent change
CA	39.48500°N	120.42500°W	6.92	percent change
CA	38.48700°N	119.80600°W	7.06	percent change
UT	40.59709°N	110.43316°W	7.13	percent change
CA	37.12200°N	118.89500°W	7.31	percent change
CA	37.13000°N	118.92000°W	7.39	percent change
CA	37.82700°N	119.49700°W	7.62	percent change
CA	36.56400°N	118.34800°W	7.78	percent change
CA	37.89700°N	119.25700°W	7.91	percent change
CA	38.31300°N	119.60700°W	7.97	percent change
CA	36.75200°N	118.75000°W	8.07	percent change
CA	36.49700°N	118.33300°W	8.10	percent change
CA	37.11300°N	118.83700°W	8.17	percent change
CA	38.51800°N	119.98500°W	8.69	percent change
UT	37.56933°N	112.83849°W	8.70	percent change
CA	37.22800°N	119.22200°W	9.06	percent change
CA	39.42752°N	120.31342°W	9.42	percent change
CA	36.71700°N	118.73700°W	9.57	percent change
CA	36.57200°N	118.36700°W	9.66	percent change
CA	37.12300°N	118.54500°W	10.18	percent change
MT	46.47535°N	112.18742°W	10.31	percent change
CA	36.61500°N	118.37700°W	10.79	percent change
CA	36.94300°N	118.91300°W	10.80	percent change
CA	36.38200°N	118.65500°W	11.29	percent change
CA	37.72400°N	119.14300°W	11.57	percent change
MT	46.78942°N	109.51205°W	12.03	percent change
CO	39.29202°N	106.54923°W	12.19	percent change
NV	39.35230°N	119.90050°W	12.23	percent change
CA	40.24300°N	121.03500°W	12.25	percent change
CA	41.20800°N	121.77500°W	13.30	percent change
OR	45.69682°N	118.10657°W	14.98	percent change
CA	37.87300°N	119.35000°W	15.66	percent change
CA	37.91700°N	119.25300°W	16.35	percent change
WA	46.54741°N	121.17093°W	16.43	percent change
NV	36.30805°N	115.69664°W	16.46	percent change
CA	37.78000°N	119.17000°W	16.51	percent change
CA	38.24300°N	119.75800°W	16.84	percent change
NV	41.75067°N	117.53182°W	16.89	percent change
CA	36.35200°N	118.26500°W	17.27	percent change
CA	36.45000°N	118.21700°W	17.51	percent change
CA	39.32565°N	120.36807°W	17.68	percent change
CA	36.12200°N	118.29300°W	18.18	percent change
CA	36.63200°N	118.39200°W	18.45	percent change
CA	36.32800°N	118.57300°W	18.47	percent change
NV	41.06662°N	115.09613°W	18.95	percent change
NV	39.31917°N	114.62278°W	18.99	percent change
UT	40.60798°N	109.88810°W	19.08	percent change
CA	37.93800°N	119.24800°W	19.34	percent change
CA	37.49700°N	119.33000°W	20.06	percent change
CA	37.49200°N	118.71700°W	20.10	percent change
CA	37.83700°N	119.32500°W	20.28	percent change
CA	37.12200°N	119.00500°W	20.47	percent change
WY	44.15178°N	110.22122°W	22.75	percent change
CO	40.15000°N	106.00000°W	22.89	percent change
UT	40.97462°N	111.80975°W	24.13	percent change
CO	40.34703°N	106.09433°W	26.05	percent change
CA	37.22800°N	118.62000°W	31.27	percent change
ID	42.32029°N	113.61587°W	34.09	percent change
CO	37.01667°N	106.45000°W	34.54	percent change
CA	36.03800°N	118.32800°W	35.98	percent change
CA	37.23500°N	118.68700°W	38.78	percent change
WY	41.25000°N	105.41667°W	40.28	percent change
CA	36.19800°N	118.27200°W	41.55	percent change
MT	45.16825°N	109.47167°W	54.64	percent change
CO	40.61667°N	105.81667°W	153.08	percent change

Figure 2. Change in Peak Snowpack Timing in the Western United States, 1982-2023

Data source: USDA Natural Resources Conservation Service, 2023⁶
Web update: June 2024

Figure data (CSV) EPA source data (CSV)

This map shows trends in the date during the year when snowpack reaches its maximum amount across the western United States. Blue triangles represent a shift to later timing; red triangles represent a shift to earlier timing.

Show the data behind this figure

State	Latitude	Longitude	Value	Unit
Colorado	37.38028°N	106.54823°W	-38.62	days
Oregon	44.42042°N	121.85655°W	-35.40	days
Washington	47.35037°N	120.67960°W	-34.38	days
Montana	48.30305°N	113.32868°W	-34.21	days
Colorado	37.33067°N	105.06766°W	-32.07	days
Colorado	39.61765°N	106.38019°W	-30.62	days
New Mexico	35.92195°N	106.39179°W	-27.10	days
Colorado	37.79895°N	107.92475°W	-26.22	days
New Mexico	36.99396°N	105.25988°W	-25.57	days
Oregon	42.69570°N	120.80158°W	-25.17	days
Colorado	39.87504°N	107.59902°W	-25.05	days
Montana	47.05678°N	112.59500°W	-24.48	days
Oregon	44.14425°N	121.64095°W	-24.32	days
Arizona	33.65352°N	109.30877°W	-24.17	days
Oregon	44.83052°N	118.18787°W	-23.97	days
Oregon	44.21007°N	118.63752°W	-23.82	days
New Mexico	36.19418°N	105.55742°W	-23.77	days
California	38.85190°N	119.93740°W	-23.45	days
Idaho	44.84237°N	114.26871°W	-22.94	days
Colorado	39.12899°N	107.28834°W	-22.63	days
California	39.17162°N	120.15362°W	-21.66	days
Utah	39.01219°N	111.58259°W	-21.31	days
Utah	38.50809°N	112.01856°W	-21.00	days
California	41.58233°N	120.30250°W	-20.85	days
Utah	39.68338°N	111.31818°W	-20.35	days
Colorado	37.61779°N	107.03932°W	-20.09	days
New Mexico	36.69935°N	105.34145°W	-20.04	days
Utah	38.48383°N	112.39273°W	-19.72	days
New Mexico	36.51174°N	106.31543°W	-19.59	days
Nevada	40.27551°N	115.54017°W	-18.92	days
Utah	41.38291°N	111.92103°W	-18.61	days
Colorado	37.48563°N	106.83528°W	-18.38	days
Montana	48.30754°N	114.84075°W	-18.38	days
Utah	40.60798°N	109.88810°W	-18.22	days
Utah	39.92976°N	111.63109°W	-18.18	days
Utah	40.35747°N	111.08993°W	-18.06	days
Utah	39.89166°N	110.74604°W	-17.64	days
Utah	41.37603°N	111.94405°W	-17.57	days
Utah	39.13400°N	111.43722°W	-17.57	days
New Mexico	36.95606°N	106.65723°W	-17.42	days
Idaho	43.60250°N	114.67417°W	-17.31	days
New Mexico	36.00152°N	106.83408°W	-17.21	days
Oregon	44.42917°N	120.33110°W	-17.18	days
Wyoming	44.47764°N	110.15651°W	-16.93	days
Utah	40.77458°N	110.01050°W	-16.78	days
Montana	44.58907°N	111.82498°W	-16.72	days
Colorado	37.99076°N	107.20392°W	-16.66	days
Utah	39.86671°N	111.28363°W	-16.59	days
Colorado	40.39591°N	106.60437°W	-16.46	days
Colorado	37.21423°N	105.12262°W	-16.42	days
Colorado	40.84758°N	106.96861°W	-16.41	days
Montana	46.24212°N	113.77250°W	-15.84	days
Utah	39.31042°N	111.43297°W	-15.64	days
Idaho	44.41470°N	113.39812°W	-15.49	days
Colorado	37.84737°N	107.72657°W	-15.46	days
Wyoming	41.32950°N	106.50250°W	-15.05	days
Idaho	44.43700°N	111.99384°W	-14.97	days
New Mexico	33.36960°N	108.70711°W	-14.94	days
Utah	38.48226°N	109.27198°W	-14.73	days
California	39.49001°N	120.28226°W	-14.67	days
Utah	38.80034°N	111.68333°W	-14.57	days
Utah	40.79669°N	110.88472°W	-14.49	days
Utah	37.83633°N	111.88163°W	-14.13	days
Utah	40.86493°N	110.79813°W	-14.11	days
Utah	37.52664°N	113.05386°W	-13.98	days
Utah	39.13683°N	111.55813°W	-13.95	days
Colorado	38.48864°N	106.33967°W	-13.81	days
Utah	40.71785°N	110.46721°W	-13.76	days
Colorado	38.89435°N	106.95327°W	-13.66	days
Montana	45.79737°N	112.52047°W	-13.64	days
Oregon	44.86887°N	118.11387°W	-13.53	days
Colorado	39.93659°N	105.59031°W	-13.47	days
Utah	40.71632°N	109.54401°W	-13.44	days
California	39.18986°N	120.26576°W	-13.30	days
Nevada	41.82098°N	116.10153°W	-13.28	days
Colorado	39.08758°N	106.54231°W	-12.97	days
Montana	46.43545°N	112.19277°W	-12.96	days
Colorado	40.31176°N	105.64670°W	-12.82	days
Montana	44.96192°N	111.29403°W	-12.74	days
Montana	45.88380°N	113.32553°W	-12.45	days
Oregon	42.53305°N	122.17683°W	-12.38	days
Utah	40.73900°N	109.67280°W	-12.31	days
Oregon	42.75333°N	118.68785°W	-12.19	days
Oregon	44.44650°N	119.93012°W	-12.16	days
Wyoming	41.15910°N	106.92809°W	-12.00	days
Utah	38.67990°N	111.59765°W	-11.63	days
Colorado	40.39803°N	105.84606°W	-11.62	days
Wyoming	43.51687°N	110.91258°W	-11.54	days
Utah	41.89833°N	111.62957°W	-11.53	days
Utah	40.44293°N	112.22377°W	-11.48	days
Colorado	39.31720°N	106.61501°W	-11.36	days
Colorado	40.53370°N	106.78140°W	-11.35	days
Wyoming	43.62728°N	107.18138°W	-11.32	days
Utah	39.45197°N	111.27221°W	-11.32	days
Idaho	42.76478°N	116.90037°W	-11.20	days
Colorado	40.41446°N	105.81941°W	-11.09	days
Colorado	37.01877°N	106.45275°W	-11.00	days
Montana	45.27190°N	110.24903°W	-10.96	days
Montana	45.00565°N	110.01406°W	-10.91	days
Idaho	42.05050°N	111.60120°W	-10.87	days
Idaho	42.16442°N	114.19272°W	-10.86	days
Colorado	39.07543°N	106.61154°W	-10.83	days
Oregon	44.24767°N	118.51722°W	-10.67	days
California	38.99927°N	120.13139°W	-10.64	days
Oregon	42.95615°N	121.18123°W	-10.57	days
Idaho	43.95380°N	115.27387°W	-10.49	days
Utah	40.58102°N	110.58587°W	-10.17	days
Nevada	41.83384°N	115.45278°W	-10.05	days
Utah	41.46547°N	111.49688°W	-9.99	days
Utah	41.40562°N	111.82607°W	-9.99	days
Utah	41.31372°N	111.44624°W	-9.88	days
Arizona	33.92123°N	109.45872°W	-9.81	days
Montana	46.35613°N	112.26176°W	-9.78	days
Oregon	43.66917°N	122.56877°W	-9.75	days
California	39.45269°N	120.29367°W	-9.69	days
Utah	40.90862°N	110.50462°W	-9.61	days
California	38.30367°N	119.55111°W	-9.58	days
Montana	47.44847°N	112.81428°W	-9.57	days
Utah	40.59709°N	110.43316°W	-9.55	days
Utah	40.85464°N	111.04765°W	-9.50	days
Montana	46.18367°N	113.85330°W	-9.50	days
Colorado	39.48917°N	106.17154°W	-9.49	days
Nevada	41.54675°N	116.00517°W	-9.45	days
Nevada	41.67032°N	117.56668°W	-9.09	days
Montana	46.46523°N	113.39358°W	-9.08	days
New Mexico	36.71632°N	106.26370°W	-8.99	days
Montana	45.21759°N	110.23700°W	-8.99	days
Wyoming	43.65868°N	109.00988°W	-8.91	days
Colorado	40.87498°N	106.04675°W	-8.87	days
Utah	39.04554°N	111.46875°W	-8.70	days
Oregon	42.70992°N	118.63210°W	-8.65	days
Montana	48.97230°N	115.95337°W	-8.54	days
California	38.43745°N	119.36572°W	-8.52	days
Nevada	39.31573°N	119.89473°W	-8.51	days
Nevada	40.89343°N	115.21104°W	-8.39	days
Colorado	40.34734°N	106.09520°W	-8.39	days
Utah	41.41289°N	111.53770°W	-8.30	days
Utah	39.93667°N	112.41478°W	-8.23	days
Montana	46.11192°N	110.46960°W	-8.15	days
Wyoming	43.38939°N	110.12943°W	-8.11	days
Oregon	45.06703°N	118.15192°W	-8.10	days
Nevada	39.29148°N	117.11506°W	-8.05	days
Wyoming	41.33087°N	106.37558°W	-7.77	days
Utah	38.77246°N	111.67662°W	-7.62	days
Montana	48.43412°N	113.93725°W	-7.53	days
Colorado	37.93389°N	107.67620°W	-7.48	days
Colorado	37.89168°N	107.71389°W	-7.48	days
Montana	44.78562°N	111.71000°W	-7.41	days
Wyoming	43.74902°N	110.05780°W	-7.36	days
Montana	46.12588°N	113.30792°W	-7.35	days
Nevada	41.76168°N	115.69310°W	-7.34	days
Utah	40.42817°N	111.61633°W	-7.23	days
Wyoming	44.73396°N	109.91484°W	-7.07	days
Utah	40.29530°N	111.25677°W	-6.98	days
Nevada	39.13242°N	114.95575°W	-6.75	days
Nevada	40.64480°N	115.38120°W	-6.71	days
Idaho	42.56248°N	111.29797°W	-6.66	days
Utah	39.89275°N	111.25154°W	-6.44	days
Oregon	43.94885°N	119.54013°W	-6.43	days
Idaho	43.86117°N	114.20902°W	-6.39	days
Wyoming	43.50278°N	109.75200°W	-6.38	days
Oregon	45.07707°N	117.55067°W	-6.37	days
Colorado	39.64646°N	105.86940°W	-6.35	days
Oregon	44.21030°N	121.87292°W	-6.30	days
Idaho	43.61040°N	113.93080°W	-6.27	days
Nevada	39.31917°N	114.62278°W	-6.20	days
Colorado	39.38014°N	106.19784°W	-6.16	days
Montana	48.90902°N	114.86298°W	-6.14	days
Oregon	42.43933°N	122.22880°W	-6.13	days
Wyoming	44.16188°N	107.12622°W	-6.09	days
Idaho	42.32029°N	113.61587°W	-6.03	days
Oregon	45.36428°N	118.46715°W	-5.92	days
Utah	37.56933°N	112.83849°W	-5.73	days
Montana	46.14380°N	114.50560°W	-5.70	days
Colorado	40.53285°N	105.88747°W	-5.64	days
Utah	37.51255°N	113.39661°W	-5.61	days
California	38.60801°N	119.92455°W	-5.59	days
Utah	37.66098°N	112.74093°W	-5.54	days
Utah	41.68541°N	111.41987°W	-5.50	days
Wyoming	44.15178°N	110.22122°W	-5.47	days
Utah	40.97462°N	111.80975°W	-5.42	days
Colorado	39.80364°N	105.77786°W	-5.20	days
Utah	37.57500°N	112.90155°W	-5.20	days
Nevada	40.38480°N	115.52757°W	-5.12	days
Wyoming	43.17387°N	110.14007°W	-5.10	days
Colorado	39.04433°N	107.87951°W	-5.07	days
Idaho	43.62903°N	115.43818°W	-5.00	days
Montana	46.14287°N	114.44755°W	-4.78	days
Montana	46.41400°N	113.43095°W	-4.71	days
Montana	44.79317°N	112.05645°W	-4.66	days
Idaho	45.69694°N	115.22972°W	-4.60	days
Montana	44.65866°N	111.09199°W	-4.59	days
California	38.54970°N	119.80468°W	-4.58	days
Utah	40.16483°N	111.20665°W	-4.55	days
Wyoming	44.80417°N	109.65700°W	-4.46	days
Nevada	39.16395°N	119.89672°W	-4.43	days
Montana	44.99380°N	113.44399°W	-4.36	days
Wyoming	43.88743°N	107.06135°W	-4.19	days
Montana	44.47147°N	112.98191°W	-4.16	days
California	38.84900°N	120.07950°W	-4.01	days
Colorado	37.20939°N	105.19988°W	-3.92	days
Montana	44.61088°N	111.14998°W	-3.57	days
Idaho	43.62600°N	113.96887°W	-3.54	days
Wyoming	41.30399°N	107.15255°W	-3.48	days
Montana	45.73107°N	114.48075°W	-3.46	days
Oregon	42.40717°N	122.26617°W	-3.39	days
Utah	38.30285°N	112.43637°W	-3.39	days
Oregon	44.65567°N	118.42617°W	-3.33	days
Nevada	41.77637°N	116.02957°W	-3.32	days
Wyoming	43.86067°N	109.32163°W	-3.18	days
Colorado	37.89169°N	108.19636°W	-3.18	days
Montana	48.15678°N	113.94637°W	-3.04	days
California	39.13545°N	120.21865°W	-3.02	days
Idaho	44.62621°N	115.79561°W	-2.93	days
Idaho	42.18072°N	114.28662°W	-2.90	days
Oregon	45.26522°N	117.17373°W	-2.80	days
Montana	47.91727°N	112.82380°W	-2.77	days
Oregon	45.32097°N	121.71580°W	-2.72	days
California	38.92431°N	119.91641°W	-2.66	days
Montana	46.77962°N	110.62165°W	-2.40	days
California	38.07298°N	119.23433°W	-2.30	days
Idaho	45.18848°N	115.97152°W	-2.28	days
Colorado	40.53740°N	106.67655°W	-2.23	days
Montana	44.94966°N	111.35852°W	-2.22	days
Wyoming	44.50012°N	107.42947°W	-2.16	days
California	38.31021°N	119.60030°W	-2.12	days
Nevada	41.75067°N	117.53182°W	-2.09	days
Idaho	42.95275°N	111.35933°W	-2.07	days
Wyoming	43.00657°N	109.75893°W	-2.05	days
Montana	45.04575°N	109.90987°W	-1.98	days
Utah	40.78931°N	111.09192°W	-1.97	days
Wyoming	44.37667°N	109.79333°W	-1.93	days
Nevada	41.87255°N	115.24713°W	-1.89	days
Montana	45.50871°N	111.92288°W	-1.87	days
Wyoming	44.72250°N	107.40033°W	-1.81	days
Nevada	41.73732°N	115.47215°W	-1.75	days
Idaho	44.60533°N	116.98097°W	-1.66	days
Montana	45.41905°N	110.08844°W	-1.55	days
Colorado	40.80572°N	105.77018°W	-1.54	days
Wyoming	44.40343°N	107.06057°W	-1.45	days
Montana	46.79279°N	110.67545°W	-1.42	days
Wyoming	44.57462°N	107.29537°W	-1.41	days
Wyoming	44.80070°N	107.84442°W	-1.38	days
Oregon	43.22625°N	121.80662°W	-1.37	days
Idaho	44.30342°N	115.23447°W	-1.17	days
Utah	38.30183°N	112.35672°W	-1.10	days
Washington	47.28734°N	120.37015°W	-1.07	days
Washington	47.99090°N	120.56622°W	-0.84	days
Montana	45.01788°N	111.84560°W	-0.79	days
Montana	45.17367°N	113.58448°W	-0.60	days
Idaho	43.71077°N	114.15894°W	-0.52	days
Montana	45.40957°N	112.95927°W	-0.49	days
Montana	46.55960°N	111.28973°W	-0.47	days
Wyoming	42.50750°N	110.90990°W	-0.35	days
Utah	37.48997°N	112.57602°W	-0.20	days
Washington	46.09497°N	121.76345°W	-0.01	days
Utah	40.88529°N	111.06954°W	0.02	days
Oregon	43.59042°N	122.06010°W	0.10	days
Utah	40.54875°N	110.69292°W	0.12	days
California	39.30087°N	120.18407°W	0.42	days
Idaho	44.28846°N	115.65508°W	0.51	days
Oregon	43.44907°N	122.13808°W	0.65	days
Montana	46.27368°N	113.16400°W	0.75	days
Montana	45.16507°N	113.50099°W	0.80	days
Washington	46.62153°N	121.38643°W	0.87	days
Oregon	42.69825°N	122.14165°W	1.21	days
Colorado	39.36092°N	106.05999°W	1.21	days
Montana	46.88293°N	113.32228°W	1.23	days
Washington	46.27143°N	121.96288°W	1.37	days
Oregon	43.90098°N	122.03063°W	1.52	days
Montana	47.08158°N	112.72955°W	1.55	days
Wyoming	44.12612°N	110.83435°W	1.58	days
California	41.99127°N	120.18033°W	1.60	days
Colorado	40.43397°N	105.73588°W	1.70	days
Wyoming	44.25602°N	106.97983°W	1.78	days
California	39.42752°N	120.31342°W	1.87	days
Montana	45.40125°N	110.95758°W	1.91	days
Montana	46.08960°N	110.43363°W	2.01	days
Wyoming	44.67888°N	107.58110°W	2.35	days
Montana	46.09713°N	113.13038°W	2.45	days
Utah	40.76184°N	111.62917°W	2.47	days
Wyoming	44.20862°N	110.66628°W	2.52	days
Wyoming	42.69525°N	108.89572°W	2.57	days
Oregon	45.19085°N	119.25392°W	2.64	days
Montana	48.79698°N	113.67050°W	2.80	days
Utah	40.67800°N	110.94873°W	3.06	days
Wyoming	41.15426°N	106.96926°W	3.23	days
Montana	48.57120°N	115.44573°W	3.80	days
Wyoming	42.86984°N	109.09455°W	3.87	days
Colorado	40.03581°N	105.54520°W	4.08	days
Montana	45.19405°N	109.34548°W	4.17	days
Montana	44.50832°N	111.12803°W	4.20	days
Colorado	40.03307°N	105.57562°W	4.63	days
Oregon	44.76380°N	118.31170°W	5.05	days
Montana	47.42749°N	113.77515°W	5.16	days
Oregon	45.42870°N	121.85605°W	5.32	days
Utah	40.61233°N	111.09782°W	5.51	days
Washington	48.44488°N	120.91551°W	5.63	days
California	38.93403°N	120.05450°W	5.64	days
Montana	44.58623°N	111.11627°W	5.88	days
Washington	47.74607°N	121.09288°W	5.98	days
Colorado	38.81982°N	106.58962°W	6.20	days
Montana	45.69259°N	113.96828°W	6.41	days
Oregon	44.26423°N	119.02162°W	6.63	days
Oregon	42.05257°N	122.85487°W	7.57	days
California	38.50576°N	119.62624°W	7.67	days
Wyoming	44.94307°N	109.56743°W	7.93	days
Montana	45.06235°N	109.94488°W	8.33	days
Montana	46.87160°N	113.27725°W	8.76	days
Washington	46.64142°N	121.38153°W	8.78	days
Montana	48.80225°N	113.85713°W	8.96	days
Montana	48.91453°N	114.76663°W	8.96	days
Montana	46.97510°N	115.03490°W	8.99	days
Oregon	43.61193°N	122.11758°W	10.68	days
Montana	46.57978°N	111.26832°W	11.59	days
Montana	47.91998°N	112.79087°W	12.04	days
Oregon	45.27173°N	117.68747°W	12.09	days
Wyoming	44.71961°N	110.51084°W	12.72	days
Montana	48.97523°N	115.81915°W	12.91	days
Oregon	45.14532°N	118.21900°W	14.82	days
Montana	46.78942°N	109.51205°W	15.10	days
Montana	45.50410°N	110.96625°W	15.93	days
Oregon	42.38010°N	122.34943°W	19.92	days
Oregon	45.69682°N	118.10657°W	20.71	days
Washington	47.23328°N	120.29412°W	25.54	days

Figure 3. Average Date of Peak Snowpack in the Western United States, 1982-2023

Data source: USDA Natural Resources Conservation Service, 2023⁶
Web update: June 2024

Figure data (CSV) EPA source data (CSV)

This graph shows trends in the date during the year when snowpack reaches its maximum amount across the western United States. The line in this graph represents an average of all the sites shown in Figure 2.

Show the data behind this figure

Water year	Peak date (day of water year)
1982	198.9
1983	209.6
1984	204.4
1985	187.9
1986	186.1
1987	186.5
1988	187.3
1989	183.3
1990	186.0
1991	199.6
1992	177.1
1993	194.2
1994	186.0
1995	199.9
1996	192.9
1997	190.1
1998	195.1
1999	199.5
2000	184.0
2001	191.0
2002	186.1
2003	194.3
2004	174.7
2005	193.7
2006	191.8
2007	177.7
2008	197.5
2009	196.6
2010	199.0
2011	206.6
2012	181.7
2013	186.6
2014	187.6
2015	164.3
2016	182.2
2017	184.1
2018	188.5
2019	191.6
2020	190.4
2021	185.7
2022	188.1
2023	195.8

Figure 4. Change in Snowpack Season Length in the Western United States, 1982–2023

Data source: USDA Natural Resources Conservation Service, 2023⁶
Web update: June 2024

Figure data (CSV) EPA source data (CSV)

This map shows trends in the length of the snowpack season across the western United States, in days. Blue circles show where the season has grown longer; red circles show where it has become shorter.

Show the data behind this figure

State	Latitude	Longitude	Value	Unit
NM	32.92000°N	108.15000°W	-89.65	days
OR	42.32000°N	120.83000°W	-81.86	days
AZ	33.98000°N	109.50000°W	-70.16	days
OR	44.42000°N	121.86000°W	-69.60	days
MT	48.30000°N	113.33000°W	-69.00	days
NV	41.52000°N	117.63000°W	-66.48	days
OR	45.53000°N	123.30000°W	-64.76	days
MT	47.06000°N	112.60000°W	-61.59	days
AZ	33.92000°N	109.46000°W	-59.73	days
NM	35.92000°N	106.39000°W	-59.45	days
AZ	33.80000°N	109.15000°W	-59.29	days
NM	33.36000°N	107.83000°W	-55.11	days
CA	39.17000°N	120.15000°W	-53.00	days
NM	36.99000°N	105.26000°W	-52.03	days
NV	41.97000°N	118.19000°W	-51.79	days
OR	44.39000°N	122.17000°W	-46.23	days
WA	47.28000°N	121.67000°W	-46.04	days
AZ	33.81000°N	110.92000°W	-43.90	days
UT	39.13000°N	111.44000°W	-43.87	days
OR	43.67000°N	122.57000°W	-42.39	days
UT	39.93000°N	111.63000°W	-41.63	days
NM	36.00000°N	106.83000°W	-40.69	days
UT	39.31000°N	111.43000°W	-40.00	days
WA	47.35000°N	120.68000°W	-39.22	days
UT	38.48000°N	112.39000°W	-39.01	days
OR	44.52000°N	122.09000°W	-38.65	days
CO	39.62000°N	106.38000°W	-38.41	days
CA	38.55000°N	119.80000°W	-37.28	days
OR	43.23000°N	121.81000°W	-36.83	days
AZ	35.14000°N	112.15000°W	-36.83	days
CA	38.44000°N	119.37000°W	-36.80	days
OR	44.14000°N	121.64000°W	-36.65	days
OR	42.13000°N	120.84000°W	-36.50	days
UT	37.57000°N	112.84000°W	-35.60	days
UT	38.51000°N	112.02000°W	-35.47	days
CA	39.45000°N	120.29000°W	-35.29	days
OR	44.44000°N	121.95000°W	-35.27	days
OR	45.19000°N	121.69000°W	-34.71	days
OR	45.04000°N	121.93000°W	-33.91	days
NM	36.19000°N	105.56000°W	-33.26	days
CA	38.07000°N	119.23000°W	-33.16	days
OR	45.54000°N	123.37000°W	-33.12	days
CA	39.49000°N	120.28000°W	-32.95	days
NM	36.51000°N	106.32000°W	-32.64	days
CA	39.19000°N	120.27000°W	-32.52	days
OR	44.43000°N	120.33000°W	-32.47	days
OR	45.19000°N	118.55000°W	-32.28	days
OR	45.43000°N	121.86000°W	-31.64	days
NM	33.74000°N	108.94000°W	-31.47	days
UT	39.89000°N	110.75000°W	-31.40	days
UT	37.66000°N	112.74000°W	-31.07	days
MT	44.79000°N	111.71000°W	-30.95	days
NM	36.70000°N	105.34000°W	-30.66	days
OR	44.59000°N	121.97000°W	-30.55	days
UT	37.58000°N	112.90000°W	-30.49	days
UT	39.45000°N	111.27000°W	-30.46	days
UT	39.14000°N	111.56000°W	-30.31	days
UT	39.01000°N	111.58000°W	-30.13	days
UT	39.94000°N	112.41000°W	-29.72	days
AZ	34.46000°N	111.41000°W	-29.71	days
UT	41.38000°N	111.94000°W	-29.29	days
UT	38.30000°N	112.36000°W	-29.26	days
UT	39.05000°N	111.47000°W	-28.34	days
OR	45.56000°N	118.45000°W	-28.28	days
UT	40.44000°N	112.22000°W	-28.20	days
UT	40.58000°N	110.59000°W	-27.63	days
UT	40.36000°N	111.09000°W	-27.43	days
ID	42.76000°N	116.90000°W	-27.39	days
UT	39.87000°N	111.28000°W	-27.32	days
UT	40.74000°N	109.67000°W	-27.26	days
CA	38.92000°N	119.92000°W	-27.15	days
MT	44.59000°N	111.82000°W	-27.13	days
NV	41.82000°N	116.10000°W	-27.11	days
MT	48.31000°N	114.84000°W	-26.85	days
NV	41.74000°N	115.47000°W	-26.72	days
MT	47.43000°N	113.78000°W	-26.57	days
OR	45.27000°N	118.85000°W	-26.16	days
MT	46.09000°N	110.43000°W	-25.86	days
OR	42.96000°N	121.18000°W	-25.49	days
NV	39.13000°N	114.96000°W	-25.47	days
UT	40.80000°N	110.88000°W	-25.14	days
UT	39.89000°N	111.25000°W	-25.02	days
NV	41.23000°N	116.03000°W	-25.01	days
CA	41.58000°N	120.30000°W	-24.76	days
UT	40.85000°N	111.05000°W	-24.75	days
UT	37.49000°N	112.58000°W	-24.53	days
CA	39.00000°N	120.13000°W	-24.44	days
UT	40.72000°N	109.54000°W	-24.44	days
NV	40.64000°N	115.38000°W	-24.28	days
OR	45.46000°N	121.70000°W	-24.15	days
UT	38.48000°N	109.27000°W	-24.11	days
UT	41.38000°N	111.92000°W	-23.35	days
NV	41.78000°N	116.03000°W	-23.19	days
MT	46.11000°N	110.47000°W	-23.18	days
OR	42.44000°N	122.23000°W	-23.04	days
WY	43.63000°N	107.18000°W	-22.73	days
OR	42.69000°N	121.43000°W	-22.73	days
UT	37.51000°N	113.40000°W	-22.53	days
UT	40.86000°N	110.80000°W	-22.48	days
UT	37.53000°N	113.05000°W	-22.46	days
NV	41.67000°N	117.57000°W	-22.41	days
CA	38.30000°N	119.55000°W	-22.36	days
OR	42.53000°N	122.18000°W	-22.34	days
MT	45.88000°N	113.33000°W	-22.29	days
OR	42.41000°N	122.27000°W	-22.23	days
WY	41.30000°N	107.15000°W	-21.82	days
NM	36.72000°N	106.26000°W	-21.80	days
ID	44.29000°N	115.66000°W	-21.31	days
CO	37.33000°N	105.07000°W	-21.31	days
UT	38.68000°N	111.60000°W	-21.25	days
MT	46.44000°N	112.19000°W	-21.15	days
OR	42.70000°N	120.80000°W	-21.00	days
MT	45.80000°N	112.52000°W	-20.70	days
CA	38.85000°N	120.08000°W	-20.21	days
NV	41.55000°N	116.01000°W	-20.19	days
OR	44.21000°N	121.87000°W	-20.07	days
WY	41.33000°N	106.50000°W	-20.00	days
CO	37.80000°N	107.92000°W	-19.65	days
ID	44.63000°N	115.80000°W	-19.45	days
UT	39.68000°N	111.32000°W	-19.45	days
MT	46.24000°N	113.77000°W	-19.36	days
CO	37.38000°N	106.55000°W	-19.35	days
CA	39.14000°N	120.22000°W	-19.32	days
MT	48.17000°N	109.65000°W	-19.23	days
OR	43.51000°N	121.98000°W	-19.23	days
NV	41.83000°N	115.45000°W	-19.05	days
MT	45.01000°N	110.01000°W	-19.02	days
UT	40.16000°N	111.21000°W	-18.99	days
NV	39.32000°N	119.89000°W	-18.98	days
MT	46.41000°N	113.43000°W	-18.94	days
UT	40.30000°N	111.26000°W	-18.72	days
OR	43.61000°N	122.12000°W	-18.58	days
UT	40.43000°N	111.62000°W	-18.05	days
ID	43.60000°N	114.67000°W	-17.80	days
OR	44.87000°N	118.11000°W	-17.78	days
CO	40.54000°N	106.68000°W	-17.23	days
NV	40.38000°N	115.53000°W	-17.03	days
UT	40.79000°N	111.09000°W	-16.91	days
OR	44.26000°N	119.02000°W	-16.89	days
MT	46.47000°N	113.39000°W	-16.71	days
CO	37.99000°N	107.20000°W	-16.66	days
MT	44.99000°N	113.44000°W	-16.52	days
WY	44.21000°N	110.67000°W	-16.18	days
MT	44.66000°N	111.09000°W	-16.11	days
MT	46.88000°N	113.32000°W	-16.03	days
CO	37.49000°N	106.84000°W	-16.00	days
CO	40.53000°N	105.89000°W	-16.00	days
UT	40.72000°N	110.47000°W	-15.91	days
OR	44.83000°N	118.19000°W	-15.86	days
WY	44.48000°N	110.16000°W	-15.76	days
UT	40.91000°N	110.50000°W	-15.73	days
OR	42.71000°N	118.63000°W	-15.67	days
OR	45.19000°N	119.25000°W	-15.61	days
ID	44.30000°N	115.23000°W	-15.58	days
CA	38.31000°N	119.60000°W	-15.51	days
OR	44.21000°N	118.64000°W	-15.47	days
MT	48.97000°N	115.95000°W	-15.44	days
CA	39.30000°N	120.18000°W	-15.36	days
UT	41.41000°N	111.83000°W	-14.99	days
WY	44.73000°N	109.91000°W	-14.62	days
MT	46.14000°N	114.51000°W	-14.53	days
WA	48.44000°N	120.92000°W	-14.51	days
UT	38.77000°N	111.68000°W	-14.33	days
OR	44.45000°N	119.93000°W	-14.01	days
UT	38.80000°N	111.68000°W	-13.64	days
OR	42.38000°N	122.35000°W	-13.49	days
MT	48.57000°N	115.45000°W	-13.31	days
MT	45.73000°N	114.48000°W	-13.05	days
OR	45.36000°N	118.47000°W	-12.62	days
UT	40.77000°N	110.01000°W	-12.37	days
OR	45.07000°N	118.15000°W	-12.33	days
UT	41.69000°N	111.42000°W	-12.23	days
WA	47.99000°N	120.57000°W	-12.20	days
OR	45.10000°N	121.75000°W	-12.19	days
CO	39.13000°N	107.29000°W	-12.12	days
OR	45.08000°N	117.55000°W	-12.01	days
UT	41.90000°N	111.63000°W	-11.92	days
UT	41.31000°N	111.45000°W	-11.84	days
NV	40.28000°N	115.54000°W	-11.77	days
WY	43.86000°N	109.32000°W	-11.55	days
MT	45.27000°N	110.25000°W	-11.45	days
OR	44.25000°N	118.52000°W	-11.43	days
MT	46.58000°N	111.27000°W	-11.40	days
CO	38.89000°N	106.95000°W	-11.39	days
NV	39.32000°N	114.62000°W	-11.28	days
UT	40.60000°N	110.43000°W	-11.04	days
UT	40.61000°N	109.89000°W	-10.92	days
MT	48.80000°N	113.67000°W	-10.61	days
CO	39.88000°N	107.60000°W	-10.60	days
OR	42.05000°N	122.85000°W	-10.53	days
CO	37.89000°N	108.20000°W	-10.43	days
WY	41.33000°N	106.38000°W	-10.39	days
WY	44.15000°N	110.22000°W	-10.36	days
UT	37.84000°N	111.88000°W	-10.34	days
ID	44.44000°N	111.99000°W	-10.33	days
WY	44.13000°N	110.83000°W	-10.25	days
MT	45.42000°N	110.09000°W	-10.00	days
WY	44.80000°N	109.66000°W	-9.86	days
UT	40.68000°N	110.95000°W	-9.84	days
OR	43.59000°N	122.06000°W	-9.67	days
OR	43.45000°N	122.14000°W	-9.36	days
UT	41.41000°N	111.54000°W	-9.12	days
ID	42.05000°N	111.60000°W	-9.12	days
WY	44.80000°N	107.84000°W	-9.11	days
MT	45.19000°N	109.35000°W	-8.99	days
NV	39.29000°N	117.12000°W	-8.93	days
NV	41.75000°N	117.53000°W	-8.91	days
CO	37.02000°N	106.45000°W	-8.54	days
WY	43.17000°N	110.14000°W	-8.51	days
NV	40.89000°N	115.21000°W	-8.51	days
MT	44.59000°N	111.12000°W	-8.51	days
OR	42.70000°N	122.14000°W	-8.43	days
CO	40.40000°N	105.85000°W	-8.34	days
CO	39.32000°N	106.62000°W	-8.05	days
CA	38.93000°N	120.05000°W	-7.83	days
UT	38.30000°N	112.44000°W	-7.66	days
MT	44.79000°N	112.06000°W	-7.50	days
UT	40.97000°N	111.81000°W	-7.50	days
MT	44.95000°N	111.36000°W	-7.45	days
CO	37.62000°N	107.04000°W	-7.22	days
CO	40.40000°N	106.60000°W	-7.16	days
WA	47.75000°N	121.09000°W	-7.15	days
CA	38.85000°N	119.94000°W	-7.13	days
ID	43.63000°N	113.97000°W	-6.94	days
UT	40.55000°N	110.69000°W	-6.89	days
CO	40.41000°N	105.82000°W	-6.87	days
CA	39.43000°N	120.31000°W	-6.76	days
WY	44.57000°N	107.30000°W	-6.69	days
NV	39.16000°N	119.90000°W	-6.64	days
MT	46.13000°N	113.31000°W	-6.53	days
WY	44.68000°N	107.58000°W	-6.50	days
MT	45.22000°N	110.24000°W	-6.38	days
WY	43.39000°N	110.13000°W	-6.30	days
NM	36.96000°N	106.66000°W	-6.06	days
MT	47.45000°N	112.81000°W	-5.78	days
MT	47.92000°N	112.82000°W	-5.66	days
WA	46.27000°N	121.96000°W	-5.65	days
WY	44.50000°N	107.43000°W	-5.52	days
UT	41.47000°N	111.50000°W	-5.37	days
MT	44.61000°N	111.15000°W	-5.26	days
CO	39.04000°N	107.88000°W	-4.91	days
WY	44.72000°N	110.51000°W	-4.77	days
MT	46.14000°N	114.45000°W	-4.76	days
CA	41.99000°N	120.18000°W	-4.74	days
WY	43.01000°N	109.76000°W	-4.47	days
UT	40.76000°N	111.63000°W	-4.29	days
CO	38.49000°N	106.34000°W	-4.29	days
ID	42.16000°N	114.19000°W	-4.11	days
CO	39.38000°N	106.20000°W	-4.08	days
MT	48.16000°N	113.95000°W	-4.07	days
MT	46.87000°N	113.28000°W	-4.02	days
MT	46.18000°N	113.85000°W	-4.00	days
WY	42.87000°N	109.09000°W	-3.95	days
CO	40.81000°N	105.77000°W	-3.65	days
MT	45.50000°N	110.97000°W	-3.64	days
ID	43.61000°N	113.93000°W	-3.62	days
WY	43.75000°N	110.06000°W	-3.51	days
OR	44.66000°N	118.43000°W	-3.25	days
OR	43.66000°N	122.21000°W	-3.24	days
WY	43.66000°N	109.01000°W	-3.10	days
ID	42.18000°N	114.29000°W	-3.09	days
MT	47.08000°N	112.73000°W	-3.00	days
MT	44.96000°N	111.29000°W	-2.64	days
MT	48.91000°N	114.86000°W	-2.51	days
MT	45.17000°N	113.50000°W	-2.14	days
WY	42.51000°N	110.91000°W	-2.10	days
WY	44.40000°N	107.06000°W	-1.94	days
CO	37.93000°N	107.68000°W	-1.85	days
MT	46.78000°N	110.62000°W	-1.25	days
MT	48.91000°N	114.77000°W	-0.83	days
CO	37.85000°N	107.73000°W	-0.29	days
WY	41.15000°N	106.97000°W	-0.12	days
MT	46.98000°N	115.03000°W	-0.03	days
ID	45.70000°N	115.23000°W	0.04	days
WY	43.52000°N	110.91000°W	0.28	days
OR	45.15000°N	118.22000°W	0.30	days
WY	44.38000°N	109.79000°W	0.34	days
WY	41.16000°N	106.93000°W	0.43	days
MT	45.02000°N	111.85000°W	0.49	days
WY	44.16000°N	107.13000°W	0.83	days
CO	37.89000°N	107.71000°W	0.91	days
UT	40.61000°N	111.10000°W	1.23	days
WY	43.50000°N	109.75000°W	1.30	days
WA	46.09000°N	121.76000°W	1.35	days
AZ	35.07000°N	111.84000°W	1.69	days
MT	46.79000°N	110.68000°W	1.73	days
MT	46.36000°N	112.26000°W	1.77	days
UT	40.89000°N	111.07000°W	1.89	days
NV	41.87000°N	115.25000°W	2.00	days
MT	47.92000°N	112.79000°W	2.02	days
MT	45.06000°N	109.94000°W	2.15	days
WY	44.26000°N	106.98000°W	2.46	days
CO	40.31000°N	105.65000°W	2.74	days
CO	40.85000°N	106.97000°W	2.79	days
MT	45.40000°N	110.96000°W	3.06	days
MT	48.80000°N	113.86000°W	3.09	days
CO	40.43000°N	105.74000°W	3.51	days
MT	45.05000°N	109.91000°W	3.76	days
WY	44.72000°N	107.40000°W	3.80	days
MT	44.51000°N	111.13000°W	4.03	days
CO	37.21000°N	105.12000°W	4.04	days
CO	39.65000°N	105.87000°W	4.16	days
CO	39.09000°N	106.54000°W	4.33	days
NV	41.76000°N	115.69000°W	4.39	days
MT	45.51000°N	111.92000°W	4.41	days
CO	39.49000°N	106.17000°W	4.69	days
CO	40.03000°N	105.58000°W	4.78	days
OR	44.76000°N	118.31000°W	4.84	days
CO	39.08000°N	106.61000°W	5.05	days
CO	39.36000°N	106.06000°W	5.15	days
WA	47.29000°N	120.37000°W	5.36	days
MT	46.10000°N	113.13000°W	5.78	days
MT	45.69000°N	113.97000°W	5.88	days
WY	42.70000°N	108.90000°W	5.90	days
CO	39.94000°N	105.59000°W	6.14	days
CA	38.51000°N	119.63000°W	6.15	days
CO	40.87000°N	106.05000°W	6.41	days
CO	40.53000°N	106.78000°W	7.53	days
CO	40.35000°N	106.10000°W	7.75	days
WY	43.89000°N	107.06000°W	7.76	days
WA	46.62000°N	121.39000°W	7.96	days
MT	45.41000°N	112.96000°W	8.86	days
MT	48.98000°N	115.82000°W	8.91	days
MT	46.27000°N	113.16000°W	9.73	days
WY	42.96000°N	110.61000°W	9.85	days
MT	45.17000°N	113.58000°W	10.03	days
CO	37.21000°N	105.20000°W	10.57	days
MT	46.56000°N	111.29000°W	10.61	days
OR	45.27000°N	117.69000°W	11.24	days
CO	40.04000°N	105.55000°W	11.32	days
OR	45.27000°N	117.17000°W	11.72	days
MT	44.47000°N	112.98000°W	12.60	days
MT	46.79000°N	109.51000°W	12.69	days
OR	45.70000°N	118.11000°W	12.79	days
OR	42.72000°N	123.20000°W	12.92	days
WY	44.94000°N	109.57000°W	13.01	days
WA	47.23000°N	120.29000°W	14.08	days
CA	38.67000°N	119.82000°W	16.11	days
CO	38.82000°N	106.59000°W	16.62	days
OR	45.55000°N	122.00000°W	18.82	days

Key Points

From 1955 to 2023, April snowpack declined at 81 percent of the sites measured (see Figure 1). The average change across all sites amounts to about an 18 percent decline.
Large and consistent decreases in April snowpack have been observed throughout the western United States (see Figure 1). Decreases have been especially prominent in Washington, Oregon, northern California, and the northern Rockies.
While some stations have experienced increases in April snowpack, all 12 states included in this indicator experienced a decrease in snowpack on average from 1955 to 2023 (see Figure 1). In the Northwest (Idaho, Oregon, Washington), all but four stations saw decreases in snowpack over the period of record.
Almost 80 percent of sites have experienced a shift toward earlier peak snowpack (see Figure 2). This earlier trend is especially pronounced in southwestern states like Colorado, New Mexico, and Utah. Across all stations, peak snowpack has shifted earlier by an average of nearly seven days since 1982 (see Figure 3), based on the long-term average rate of change.
From 1982 to 2023, the snowpack season became shorter at about 80 percent of the sites where snowpack was measured (see Figure 4). Across all sites, the length of the snowpack season decreased by about 15 days, on average.

Background

Temperature and precipitation are key factors affecting snowpack, which is the amount or thickness of snow that accumulates on the ground. In a warming climate, more precipitation will be expected to fall as rain rather than snow in most areas—reducing the extent and depth of snowpack. Long-term observations across the contiguous 48 states show that nearly 80 percent of weather stations examined have experienced a decrease in the proportion of precipitation falling as snow (see the Snowfall indicator). In addition, with warmer winters and springs (see the Seasonal Temperature indicator), the seasonality of snowpack is also changing. Higher temperatures cause snow to melt earlier, which in turn affects the timing and availability of water.

Mountain snowpack plays a key role in the water cycle in western North America, storing water in the winter when the snow falls and releasing it as runoff in spring and summer when the snow melts. Millions of people in the West depend on the melting of mountain snowpack for hydropower, irrigation, and drinking water. In most western river basins, snowpack is a larger component of water storage than human-constructed reservoirs.¹ Continued reductions in snowpack and shifts in snowmelt are expected in the future, which will reduce hydropower production in the West.²

Changes in mountain snowpack can affect agriculture, winter recreation, and tourism in some areas, as well as plants and wildlife. For example, certain types of trees rely on snow for insulation from freezing temperatures, as do some animal species. In addition, fish spawning could be disrupted if changes in snowpack or snowmelt alter the timing and abundance of streamflows. (For a look at long-term trends in the timing of spring snowmelt runoff in United States, see the Streamflow indicator.) Additionally, warming and earlier snowmelt accelerate the start of the wildfire season and promote more wildfire activity in the western United States and Alaska (see the Wildfires indicator).^3,4 Altogether, snowpack’s sensitivity to climate and its many related effects make this a valuable indicator to track.

About the Indicator

This indicator uses a measurement called snow water equivalent to determine trends in snowpack. Snow water equivalent is the amount of water contained within the snowpack at a particular location. It can be thought of as the depth of water that would result if the entire snowpack were to melt. Figure 1 shows long-term rates of change for April 1, the most frequent observation date, because it could reflect changes in precipitation, and it is extensively used for spring streamflow and water supply forecasting. Figures 2 and 3 focus on the day of each year when snowpack is at its deepest (that is, peak snowpack) to determine if it is occurring earlier or later. Figure 4 shows changes in the length of the snowpack season, representing the number of days when the ground is covered by continuous snowpack.

The U.S. Department of Agriculture and other collaborators have measured snowpack since the early 1900s. In the early years of data collection, researchers measured snow water equivalent manually, but since 1980, measurements at some locations have been collected with automated instruments as part of the snow telemetry (SNOTEL) network. The long-term analysis in Figure 1 is based on data from nearly 700 permanent measurement sites in the western United States. The snowpack analysis shown in Figures 2, 3 and 4 requires daily measurements, so it uses a smaller set of 340 SNOTEL sites that have data since 1982, which is when a large number of SNOTEL devices were deployed and came online.

About the Data

Indicator Notes

EPA selected 1955 as a starting point for Figure 1 because many measurement sites in the Southwest were established in the early 1950s. Natural variability in the Earth’s climate means that snowpack trends may vary slightly when measured over different time periods. For example, the period from 1945 to 1955 was unusually snowy in the Northwest, so if this indicator were to start in 1945 or 1950, the Northwest would appear to show larger decreases over time. However, the general direction of the trend is the same regardless of the start date. Analysis of the peak snowpack in Figures 2, 3, and 4 is limited to automated SNOTEL stations, which results in a shorter time period and a smaller number of stations than Figure 1. These analyses are less subject to year-to-year variation than a time series based on a single date like April 1, but snowpack conditions during the first few years (in this case, the early to mid-1980s) could still have a sizable influence on the trends calculated for this indicator.

Although most parts of the West have seen reductions in snowpack―consistent with overall warming trends shown in the U.S. and Global Temperature indicator―snowfall trends may be partially influenced by non-climatic factors such as observation methods, land-use changes, and forest canopy changes. This indicator applies consistent methods to all locations, but each site naturally has unique local conditions and a unique distribution of data. For many of the areas where snowpack is increasing, studies have documented that despite general increases in temperature and precipitation, temperatures often remain below the freezing point, resulting in more snowfall.^7,8

Data Sources

Data for this indicator came from the U.S. Department of Agriculture’s Natural Resources Conservation Service Water and Climate Center. The April 1 trend analysis for this indicator was constructed using methods consistent with Mote et al. (2005) and Mote et al. (2018),^1,9 the peak snowpack analysis was adapted from work by Evan (2019),¹⁰ and snowpack season length was calculated using methods from Petersky and Harpold (2018).¹¹ The U.S. Department of Agriculture data are available at: www.wcc.nrcs.usda.gov.

Technical Documentation

Download related technical information (PDF)

References

Mote, P. W., Hamlet, A. F., Clark, M. P., & Lettenmaier, D. P. (2005). Declining mountain snowpack in western North America. Bulletin of the American Meteorological Society, 86(1), 39–50. https://doi.org/10.1175/BAMS-86-1-39
Payton, E. A., Pinson, A. O., Asefa, T., Condon, L. E., Dupigny-Giroux, L.-A. L., Harding, B. L., Kiang, J., Lee, D. H., McAfee, S. A., Pflug, J., Rangwala, I., Tanana, H. J., & Wright, D. B. (2023). Chapter 4: Water. In USGCRP (U.S. Global Change Research Program), Fifth National Climate Assessment. https://doi.org/10.7930/NCA5.2023.CH4
Westerling, A. L. (2016). Increasing western US forest wildfire activity: Sensitivity to changes in the timing of spring. Philosophical Transactions of the Royal Society B: Biological Sciences, 371(1696), 20150178. https://doi.org/10.1098/rstb.2015.0178
Kitzberger, T., Falk, D. A., Westerling, A. L., & Swetnam, T. W. (2017). Direct and indirect climate controls predict heterogeneous early-mid 21st century wildfire burned area across western and boreal North America. PLOS ONE, 12(12), e0188486. https://doi.org/10.1371/journal.pone.0188486
USDA (U.S. Department of Agriculture) Natural Resources Conservation Service. (2024). Snow telemetry (SNOTEL) and snow course data and products. Retrieved January 2, 2024, from www.drought.gov/data-maps-tools/nrcs-snotel-and-snow-course-data
USDA (U.S. Department of Agriculture) Natural Resources Conservation Service. (2023). Snow telemetry (SNOTEL) and snow course data and products. Retrieved October 1, 2023, from www.drought.gov/data-maps-tools/nrcs-snotel-and-snow-course-data
Luce, C. H., Lopez-Burgos, V., & Holden, Z. (2014). Sensitivity of snowpack storage to precipitation and temperature using spatial and temporal analog models. Water Resources Research, 50(12), 9447–9462. https://doi.org/10.1002/2013WR014844
Scalzitti, J., Strong, C., & Kochanski, A. (2016). Climate change impact on the roles of temperature and precipitation in western U.S. snowpack variability. Geophysical Research Letters, 43(10), 5361–5369. https://doi.org/10.1002/2016GL068798
Mote, P. W., Li, S., Lettenmaier, D. P., Xiao, M., & Engel, R. (2018). Dramatic declines in snowpack in the western US. Climate and Atmospheric Science, 1, 2. https://doi.org/10.1038/s41612-018-0012-1
Evan, A. T. (2019). A new method to characterize changes in the seasonal cycle of snowpack. Journal of Applied Meteorology and Climatology, 58(1), 131–143. https://doi.org/10.1175/JAMC-D-18-0150.1
Petersky, R., & Harpold, A. (2018). Now you see it, now you don’t: A case study of ephemeral snowpacks and soil moisture response in the Great Basin, USA. Hydrology and Earth System Sciences, 22(9), 4891–4906. https://doi.org/10.5194/hess-22-4891-2018

Text on this page is EPA’s own published wording (a U.S. Government work, not subject to domestic copyright), extracted from EPA’s published indicator page and verified paragraph by paragraph against the archived HTML. Data, chart code, and the full extraction pipeline are maintained in the snowpack repository, which this page reads its data from directly.