Wildfires

Environment

Wildfires

This indicator tracks the frequency, extent, and severity of wildfires in the United States.

Figures

Figure 1. Wildfire Frequency in the United States, 1983-2022

Data source: NIFC, 2024; USDA Forest Service, 2014
Web update: June 2024

Figure 1

This figure shows the total number of wildfires per year from 1983 to 2022. These totals include all reported wildfires, which can be as small as just a few acres. The two lines represent two different reporting systems; though the Forest Service stopped collecting statistics (orange line) in 1997 and will not update them, those statistics are shown here for comparison.

Show the data behind this figure

Year	National Interagency Fire Center	Forest Service Wildfire Statistics
1983	18,229	95,169
1984	20,493	118,178
1985	82,591	133,802
1986	85,907	140,545
1987	71,300	143,877
1988	72,750	154,573
1989	48,949	120,095
1990	66,481	122,043
1991	75,754	116,953
1992	87,394	103,830
1993	58,810	97,031
1994	79,107	114,049
1995	82,234	130,019
1996	96,363	115,025
1997	66,196	89,393
1998	81,043
1999	92,487
2000	92,250
2001	84,079
2002	73,457
2003	63,629
2004	65,461
2005	66,753
2006	96,385
2007	85,705
2008	78,979
2009	78,792
2010	71,971
2011	74,126
2012	67,774
2013	47,579
2014	63,312
2015	68,151
2016	67,743
2017	71,499
2018	58,083
2019	50,477
2020	58,950
2021	58,985
2022	68,988

Figure 2

Figure 2. Wildfire Extent in the United States, 1983-2022

Data source: NIFC, 2024; Short, 2015
Web update: June 2024

Figure data (CSV) EPA source data (CSV)

Figure 3

This figure shows annual wildfire-burned area (in millions of acres) from 1983 to 2022. The two lines represent two different reporting systems though the Forest Service stopped collecting statistics (orange line) in 1997 and is not planning to update them, those statistics are shown here for comparison.

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Year	National Interagency Fire Center	Forest Service Wildfire Statistics
1983	1,323,666	5,080,553
1984	1,148,409	2,266,276
1985	2,896,147	4,434,768
1986	2,719,162	3,309,398
1987	2,447,296	4,152,524
1988	5,009,290	7,398,846
1989	1,827,310	3,261,702
1990	4,621,621	5,452,818
1991	2,953,578	2,237,714
1992	2,069,929	2,457,665
1993	1,797,574	2,310,420
1994	4,073,579	4,724,014
1995	1,840,546	2,315,730
1996	6,065,998	6,701,390
1997	2,856,959	3,672,616
1998	1,329,704
1999	5,626,093
2000	7,393,493
2001	3,570,911
2002	7,184,712
2003	3,960,842
2004	8,097,880
2005	8,689,389
2006	9,873,745
2007	9,328,045
2008	5,292,468
2009	5,921,786
2010	3,422,724
2011	8,711,367
2012	9,326,238
2013	4,319,546
2014	3,595,613
2015	10,125,149
2016	5,509,995
2017	10,026,086
2018	8,767,492
2019	4,664,364
2020	10,122,336
2021	7,125,643
2022	7,577,183

Figure 4

Figure 3. Damage Caused by Wildfires in the United States, 1984-2021

Data source: MTBS, 2024
Web update: June 2024

Figure data (CSV) EPA source data (CSV)

Figure 5

This figure shows the distribution of acreage burned by large wildfires, based on the level of damage caused to the landscape—a measure of wildfire severity. Large wildfires are defined as fires with an area larger than 1,000 acres in the western United States and 500 acres in the eastern United States. The total acreage shown in Figure 3 is slightly less than the total in Figure 2 because Figure 3 is limited to large fires and because a few areas did not have sufficient satellite imagery to allow damage to be assessed.

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Year	Low	Moderate	High	Unburned	Increased greenness
1984	711,517	165,303	58,695	277,214	16,309
1985	1,568,281	702,452	247,655	541,103	60,754
1986	987,523	415,182	107,691	283,268	20,181
1987	1,092,490	421,080	201,226	532,639	35,364
1988	1,608,268	877,754	819,880	1,024,001	252,230
1989	836,318	234,073	142,001	217,759	7,594
1990	945,166	579,665	464,195	365,840	224,351
1991	875,287	417,019	157,885	342,563	71,043
1992	668,200	205,779	110,843	313,789	13,384
1993	657,086	341,605	113,911	223,843	23,932
1994	1,336,230	709,298	370,841	691,702	37,819
1995	658,099	312,745	64,178	197,470	6,421
1996	2,471,947	1,109,685	352,752	871,746	24,527
1997	308,032	96,326	29,375	127,662	23,784
1998	867,085	228,466	120,346	296,355	28,456
1999	2,512,574	1,077,773	440,200	900,276	53,582
2000	2,612,716	1,246,627	839,606	1,412,897	69,485
2001	1,211,279	528,657	224,364	530,536	16,997
2002	1,923,555	1,603,891	1,111,012	1,019,393	172,946
2003	1,155,778	787,846	635,284	749,563	89,737
2004	1,911,788	2,001,070	734,912	1,177,344	1,114,652
2005	2,795,213	2,066,900	1,559,041	1,455,244	876,246
2006	3,596,275	1,751,958	636,276	1,423,822	72,509
2007	2,882,533	1,678,554	1,185,021	1,656,594	143,812
2008	1,772,243	798,869	296,171	756,044	15,081
2009	1,408,486	921,465	578,123	516,778	41,525
2010	1,134,234	411,757	207,297	297,823	112,460
2011	4,608,989	1,480,142	411,398	1,084,386	71,712
2012	3,812,837	1,530,226	680,169	1,250,944	49,550
2013	1,363,012	948,714	669,574	473,139	134,060
2014	1,469,241	576,968	367,597	378,906	44,654
2015	2,991,385	2,299,623	1,972,691	1,157,742	525,883
2016	2,352,619	778,266	377,998	586,319	56,552
2017	5,175,922	1,557,908	824,143	1,224,119	67,492
2018	3,957,293	1,827,183	688,838	855,147	23,473
2019	2,053,493	1,183,999	316,860	508,647	103,082
2020	4,476,422	2,252,328	1,602,475	1,247,574	40,062
2021	3,143,222	1,449,091	1,005,343	1,106,933	29,434

Figure 6

Figure 4. Average Annual Burned Acreage by State, 1984-2021

Data source: MTBS, 2024
Web update: June 2024

Figure data (CSV) Annual burned acreage by state (CSV) EPA source data (CSV)

Figure 7

This map shows the average number of acres burned in each state per year as a proportion of that state’s total land area. Darker-shaded states have the largest proportion of acreage burned. For reference, there are 640 acres in a square mile; therefore, an average burned area of 6.4 acres per square mile would mean that fires burned 1 percent of a state’s total land area. States that did not have any fires that were large enough to be included in this analysis are shaded gray.

This site’s basemap does not include Alaska or Hawaii, so Alaska and Hawaii (which both report data) are omitted from the map above but included in the table below.

Show the data behind this figure

State	Trend (acres per square mile)
Alabama	0.063
Alaska	1.624
Arizona	1.823
Arkansas	0.092
California	4.093
Colorado	0.756
Delaware	0.017
Florida	1.689
Georgia	0.698
Hawaii	0.603
Idaho	5.603
Indiana	0.005
Iowa	0.002
Kansas	0.398
Kentucky	0.271
Louisiana	0.182
Maine	0.003
Maryland	0.080
Massachusetts	0.006
Michigan	0.054
Minnesota	0.430
Mississippi	0.110
Missouri	0.066
Montana	1.674
Nebraska	0.297
Nevada	3.123
New Jersey	0.424
New Mexico	1.377
New York	0.020
North Carolina	0.323
North Dakota	0.110
Ohio	0.003
Oklahoma	1.510
Oregon	3.471
Pennsylvania	0.013
South Carolina	0.105
South Dakota	0.387
Tennessee	0.108
Texas	0.789
Utah	1.701
Virginia	0.119
Washington	3.026
West Virginia	0.943
Wisconsin	0.008
Wyoming	1.216

Figure 8

Figure 5. Change in Annual Burned Acreage by State Between 1984-2002 and 2003-2021

Data source: MTBS, 2024
Web update: June 2024

Figure data (CSV) EPA source data (CSV)

Figure 9

This map shows how the number of acres burned in each state as a proportion of that state’s total land area has changed over time, based on a simple comparison between the first half of the available years (1984–2002) and the second half (2003–2021). For reference, there are 640 acres in a square mile; therefore, a change of 6.4 acres per square mile would mean that burned area increased by 1 percent of a state’s total land area. States that did not have any fires that were large enough to be included in this analysis are shaded gray.

This site’s basemap does not include Alaska or Hawaii, so Alaska and Hawaii (which both report data) are omitted from the map above but included in the table below.

Show the data behind this figure

State	Change
West Virginia	-1.746
Kentucky	-0.331
Wyoming	-0.177
New Jersey	-0.163
Minnesota	-0.101
Florida	-0.087
South Dakota	-0.055
North Carolina	-0.044
Delaware	-0.033
Nebraska	-0.017
New York	-0.014
North Dakota	-0.014
Maine	-0.003
Tennessee	+0.002
Indiana	+0.003
Iowa	+0.004
Ohio	+0.006
Wisconsin	+0.010
Massachusetts	+0.012
South Carolina	+0.016
Michigan	+0.020
Pennsylvania	+0.026
Alabama	+0.041
Missouri	+0.076
Mississippi	+0.079
Louisiana	+0.096
Arkansas	+0.106
Virginia	+0.117
Kansas	+0.140
Maryland	+0.152
Colorado	+0.644
Utah	+0.649
New Mexico	+0.891
Georgia	+0.910
Nevada	+0.946
Hawaii	+1.099
Texas	+1.137
Montana	+1.346
Alaska	+1.592
Arizona	+2.024
Oregon	+2.298
Idaho	+2.648
Oklahoma	+2.649
Washington	+3.522
California	+4.166

Figure 10

Figure 6. Comparison of Monthly Burned Area Due to Wildfires in the United States Between 1984–2002 and 2003–2021

Data source: MTBS, 2023
Web update: June 2024

Figure data (CSV) EPA source data (CSV)

Figure 11

This figure compares the annual distribution of burned area due to wildfires in the United States between the first half of the period of measurement (1984–2002) and the second half (2003–2021).

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Month	1984-2002	2003-2021
January	0.011	0.035
February	0.036	0.076
March	0.080	0.264
April	0.110	0.316
May	0.141	0.342
June	0.554	1.520
July	0.767	1.788
August	0.803	1.318
September	0.123	0.369
October	0.099	0.142
November	0.057	0.050
December	0.006	0.041

Figure 12

Figure 7. Comparison of Monthly Burned Area Due to Wildfires in the Eastern and Western United States Between 1984-2002 and 2003-2021

Data source: MTBS, 2023
Web update: June 2024

Figure data (CSV) EPA source data (CSV)

Figure 13

This figure compares the annual distribution of burned area due to wildfires in the eastern and western United States between the first half of the period of measurement (1984–2002) and the second half (2003–2021).

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Region	Month	1984-2002	2003-2021
East	January	0.002	0.005
East	February	0.011	0.017
East	March	0.018	0.034
East	April	0.066	0.080
East	May	0.038	0.055
East	June	0.024	0.022
East	July	0.011	0.015
East	August	0.004	0.013
East	September	0.005	0.004
East	October	0.031	0.008
East	November	0.043	0.013
East	December	0.002	0.002
West	January	0.009	0.031
West	February	0.025	0.059
West	March	0.062	0.230
West	April	0.045	0.237
West	May	0.103	0.287
West	June	0.529	1.499
West	July	0.756	1.773
West	August	0.799	1.304
West	September	0.118	0.365
West	October	0.069	0.134
West	November	0.014	0.037
West	December	0.004	0.039

Figure 14

Key Points

Since 1983, the National Interagency Fire Center has documented an average of approximately 70,000 wildfires per year (Figure 1). Compiled data from the Forest Service suggest that the actual total may be even higher for the first few years of nationwide data collection that can be compared. The data do not show an obvious trend during this time.
The extent of area burned by wildfires each year appears to have increased since the 1980s. According to National Interagency Fire Center data, of the 10 years with the largest acreage burned, all have occurred since 2004, including the peak years in 2015 and 2020 (Figure 2). This period coincides with many of the warmest years on record nationwide (see the U.S. and Global Temperature indicator). The largest increases have occurred during the spring and summer months (Figure 6).
The late 1990s were a period of transition in certain climate cycles that tend to shift every few decades.¹⁵ This shift—combined with other ongoing changes in temperature, drought, and snowmelt—may have contributed to warmer, drier conditions that have fueled wildfires in parts of the western United States.^3,16
Of the total area burned each year from 1984 to 2021, the proportion of burned land suffering severe damage has ranged from 5 to 22 percent (see the “high” category in Figure 3).
Land area burned by wildfires varies by state. Fires burn more land in the western United States than in the East, and parts of the West and Southwest show the largest increase in burned acreage between the first half of the period of record in Figures 4 and 5 (1984–2002) and the second half (2003–2021) (Figure 5). Burned acreage in the West has increased noticeably in nearly every month of the year (Figure 7).
The peak of the U.S. wildfire season is occurring earlier (Figure 6). In 1984–2002, burned area peaked in August. More recently, it has peaked in July. An average of 1.8 million acres burned in July of each year from 2003 to 2021.

Background

Together, forests, shrubland, and grassland cover more than half of the land area in the United States.¹ These ecosystems are important resources, both environmentally and economically. Although wildfires occur naturally and play a long-term role in the health of these ecosystems, changing wildfire patterns threaten to upset the status quo. Multiple studies have found that climate change has already led to an increase in wildfire season length, wildfire frequency, and burned area.²³ The wildfire season has lengthened in many areas due to factors including warmer springs, longer summer dry seasons, and drier soils and vegetation.² Similarly, climate change threatens to increase the frequency, extent, and severity of fires through increased temperatures and drought (see the U.S. and Global Temperature and Drought indicators).² Earlier spring melting and reduced snowpack (see the Snowpack indicator) result in decreased water availability during hot summer conditions, which in turn contributes to an increased wildfire risk, allowing fires to start more easily and burn hotter. These trends of longer wildfire seasons and larger wildfire size are predicted to continue as more frequent and longer droughts occur.² In addition to climate change, other factors—land use, large-scale insect infestation, fuel availability (including invasive species such as highly flammable cheatgrass), and management practices, including fire suppression—play an important role in wildfire frequency and intensity. All of these factors influencing wildfires vary greatly by region and over time, as do precipitation, wind, temperature, vegetation types, and landscape conditions. Therefore, understanding changes in fire characteristics requires long-term records, a regional perspective, and consideration of many factors.⁴

Wildfires have the potential to harm property, livelihoods, and human health. Fire-related threats are increasing, especially as more people live in and near forests, grasslands, and other natural areas.⁵ According to the National Oceanic and Atmospheric Administration, between 1980 and 2023 the United States had 22 wildfire events that individually caused more than $1 billion in damage; 18 of those have occurred since 2000.⁶ Over the past few decades, the United States has routinely spent more than $1 billion per year to fight wildfires, including $3.5 billion in 2022.⁷ These efforts have resulted in the deaths of hundreds of firefighters.⁸ Even in communities far downwind, wildfire smoke has been directly linked to poor air quality that can lead to significant health effects and costs to society (emergency department visits, hospital admissions, and deaths, often due to respiratory ailments).⁹¹³

Beyond the human and societal impacts, wildfires also affect the Earth’s climate. Forests in particular store large amounts of carbon. When they burn, they immediately release carbon dioxide into the atmosphere, which in turn contributes to climate change. After burning, forests also release carbon dioxide more gradually through decomposition.

About the Indicator

This indicator defines a wildfire as “a wildland fire originating from an unplanned ignition, such as lightning, volcanos, unauthorized and accidental human caused fires, and prescribed fires that are declared wildfires.”¹⁴ This indicator tracks four aspects of wildfires over time: the total number of fires (frequency), the total land area burned (extent), the degree of damage that fires cause to the landscape (severity), and the acreage burned by fires starting in each month of the year (seasonal patterns).

The total area and total number of fires are tracked by the National Interagency Fire Center, which compiles reports from local, state, and federal agencies that are involved in fighting wildfires. The U.S. Forest Service tracked similar data using a different reporting system until 1997. Those data have been added to this indicator for comparison. Burn severity, state-level acreage, and monthly totals are based on data from the Monitoring Trends in Burn Severity (MTBS) project, which provides the location, ignition date, size, and other statistics for every individual wildfire that meets certain size criteria (≥ 1,000 acres in the western United States or ≥ 500 acres in the eastern United States). MTBS compares the “greenness” of satellite images taken before and after a fire to classify how severely the land has been burned. Burn severity provides an indication of the ecological damage and how long the effects of wildfires are likely to last.

Although some nationwide fire data have been collected since the early 1900s, this indicator starts in 1983 (Figures 1 and 2) and 1984 (Figures 3 through 7), when nationwide data collection became more complete and standardized. EPA divided the time period in Figures 5, 6, and 7 into two roughly equal halves to compare changes in wildfire characteristics over time.

About the Data

Indicator Notes

Many environmental impacts associated with climate change can affect the severity and timing of the wildfire season, including changes in temperature, precipitation, and drought. Short-term weather conditions (dryness, temperature, wind, lightning) influence the likelihood of ignition, where and how quickly a fire spreads, and how big it gets. Longer-term climate patterns also play a role by creating conditions that may be conducive to wildfire (for example, a multi-year regional drought). Human activities and land management practices also affect wildfire activity, and preferred practices in wildfire management have evolved over time, from older policies that favored complete wildfire prevention to more recent policies of wildfire suppression and controlled burns. Resources available to fight and manage wildfires can also influence the amount of area burned over time.

While this indicator is limited to “wildland” fires, it includes fires that encroach on—or perhaps started in—developed areas. Increased development in previously wild lands could also influence trends in wildfire frequency and extent. The total number of fires may also vary due to reporting irregularities, as fires that split or merge together across jurisdictional lines may be counted differently.

Along with the influence of ongoing climate change, wildfire patterns can be influenced by natural climate cycles that tend to shift every few decades. Thus, with less than four decades of data shown here, it might be challenging to draw conclusions about long-term trends. While a longer record would be ideal, data from before 1983 are not consistent or detailed enough nationally to be included in this indicator.

Data Sources

The full set of wildfire frequency and burned acreage data in Figures 1 and 2 comes from the National Interagency Fire Center, which compiles wildfire reports sent from local, state, and federal entities that are involved in fighting fires. These data are available online at: www.nifc.gov/fire-information/statistics. Additional data were provided by the U.S. Forest Service based on a different set of records, referred to as Smokey Bear Reports. Burn severity data, state-by-state acreage totals, and monthly acreage data in Figures 3 through 7 come from the MTBS multi-agency project, which maintains a database of wildfire events across the United States. These data are publicly available at: www.mtbs.gov/direct-download.

Technical Documentation

Download related technical information (PDF)

References

MRLC (Multi-Resolution Land Characteristics) Consortium. (2019). National Land Cover Database 2016 (NLCD2016) statistics for 2016. www.mrlc.gov/data/statistics/national-land-cover-database-2016-nlcd2016-statistics-2016
Ostoja, S. M., Crimmins, A. R., Byron, R. G., East, A. E., Méndez, M., O’Neill, S. M., Peterson, D. L., Pierce, J. R., Raymond, C., Tripati, A., & Vaidyanathan, A. (2023). Focus on western wildfires. In USGCRP (U.S. Global Change Research Program), Fifth National Climate Assessment. https://doi.org/10.7930/NCA5.2023.F2
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
Stein, S. M., Menakis, J., Carr, M. A., Comas, S. J., Stewart, S. I., Cleveland, H., Bramwell, L., & Radeloff, V. C. (2013). Wildfire, wildlands, and people: Understanding and preparing for wildfire in the wildland-urban interface (General Technical Report RMRS-GTR-299). United States Department of Agriculture. www.fs.usda.gov/research/treesearch/43016
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Johnston, F. H., Henderson, S. B., Chen, Y., Randerson, J. T., Marlier, M., DeFries, R. S., Kinney, P., Bowman, D. M. J. S., & Brauer, M. (2012). Estimated global mortality attributable to smoke from landscape fires. Environmental Health Perspectives, 120(5), 695–701. https://doi.org/10.1289/ehp.1104422
Fann, N., Brennan, T., Dolwick, P., Gamble, J. L., Ilacqua, V., Kolb, L., Nolte, C. G., Spero, T. L., & Ziska, L. (2016). Chapter 3: Air quality impacts. In USGCRP (U.S. Global Change Research Program), The impacts of climate change on human health in the United States: A scientific assessment (pp. 69–98). https://doi.org/10.7930/J0GQ6Vp6
Youssouf, H., Liousse, C., Roblou, L., Assamoi, E.-M., Salonen, R., Maesano, C., Banerjee, S., & Annesi-Maesano, I. (2014). Non-accidental health impacts of wildfire smoke. International Journal of Environmental Research and Public Health, 11(11), 11772–11804. https://doi.org/10.3390/ijerph111111772
Jones, B. A., & Berrens, R. P. (2017). Application of an original wildfire smoke health cost benefits transfer protocol to the western U.S., 2005–2015. Environmental Management, 60(5), 809–822. https://doi.org/10.1007/s00267-017-0930-4
Fann, N., Alman, B., Broome, R. A., Morgan, G. G., Johnston, F. H., Pouliot, G., & Rappold, A. G. (2018). The health impacts and economic value of wildland fire episodes in the U.S.: 2008–2012. Science of the Total Environment, 610–611, 802–809. https://doi.org/10.1016/j.scitotenv.2017.08.024
NWCG (National Wildfire Coordinating Group). (2020). Glossary of wildland fire terminology. www.nwcg.gov/publications/pms205
Peterson, W. T., & Schwing, F. B. (2003). A new climate regime in northeast Pacific ecosystems. Geophysical Research Letters, 30(17), 2003GL017528. https://doi.org/10.1029/2003GL017528
Kitzberger, T., Brown, P. M., Heyerdahl, E. K., Swetnam, T. W., & Veblen, T. T. (2007). Contingent Pacific–Atlantic Ocean influence on multicentury wildfire synchrony over western North America. Proceedings of the National Academy of Sciences, 104(2), 543–548. https://doi.org/10.1073/pnas.0606078104
NIFC (National Interagency Fire Center). (2024). Total wildland fires and acres (1983–2023) [Data set]. Retrieved February 21, 2024, from www.nifc.gov/fireInfo/fireInfo_stats_totalFires.html
USDA (U.S. Department of Agriculture) Forest Service. (2014). 1991–1997 wildland fire statistics (prepared by USDA Forest Service, State and Private Forestry, Fire and Aviation Management staff, and supplemented with historical records provided by Forest Service staff, April 2014) [Data set].
Short, K. C. (2015). Sources and implications of bias and uncertainty in a century of US wildfire activity data. International Journal of Wildland Fire, 24(7), 883–891. https://doi.org/10.1071/WF14190
MTBS (Monitoring Trends in Burn Severity). (2024). Direct download. Retrieved February 1, 2024, from www.mtbs.gov/direct-download
MTBS (Monitoring Trends in Burn Severity). (2023). Direct download. Retrieved December 1, 2023, from www.mtbs.gov/direct-download

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