Stream Temperature

Weather and Climate
Stream Temperature
This indicator shows how stream water temperatures have changed at 129 stream gauges across the Chesapeake Bay region from 1960 to 2014.

Figures

Figure 1. Changes in Stream Water Temperatures in the Chesapeake Bay Region, 1960–2014

Data source: Jastram and Rice, 2015.
Web update: August 2016

Figure data (CSV) EPA source data (CSV)

Figure 1

This map shows the change in water temperature at 129 stream gauges across the Chesapeake Bay region from 1960 to 2014. Red circles show locations where temperatures have increased; blue circles show locations where temperatures have decreased. Filled circles represent sites where the change was statistically significant.

Show the data behind this figure
Latitude Longitude Trend (°F per year) Total change (°F)
44 40.463°N 78.200°W -0.1458 -7.8732
53 39.879°N 76.853°W -0.1008 -5.4432
35 40.943°N 77.786°W -0.0972 -5.2488
122 40.889°N 80.337°W -0.0846 -4.5684
95 41.486°N 78.678°W -0.0810 -4.3740
125 40.763°N 80.315°W -0.0576 -3.1104
80 37.307°N 78.389°W -0.0414 -2.2356
36 41.052°N 77.604°W -0.0378 -2.0412
33 41.320°N 77.874°W -0.0306 -1.6524
100 40.655°N 79.349°W -0.0288 -1.5552
32 41.476°N 77.826°W -0.0270 -1.4580
103 40.419°N 79.026°W -0.0234 -1.2636
25 41.359°N 75.744°W -0.0216 -1.1664
24 41.505°N 75.542°W -0.0198 -1.0692
30 41.317°N 78.103°W -0.0198 -1.0692
4 39.699°N 75.675°W -0.0162 -0.8748
3 39.761°N 75.519°W -0.0144 -0.7776
115 39.820°N 79.321°W -0.0144 -0.7776
37 41.060°N 77.606°W -0.0108 -0.5832
38 41.522°N 77.447°W -0.0108 -0.5832
39 41.474°N 77.231°W -0.0090 -0.4860
105 40.517°N 79.172°W -0.0072 -0.3888
12 38.214°N 75.671°W -0.0054 -0.2916
5 39.763°N 75.637°W -0.0018 -0.0972
13 38.728°N 75.562°W -0.0018 -0.0972
118 40.240°N 79.807°W -0.0018 -0.0972
60 39.302°N 79.307°W 0.0000 0.0000
61 39.570°N 79.102°W 0.0018 0.0972
97 40.995°N 79.394°W 0.0018 0.0972
107 40.605°N 79.552°W 0.0018 0.0972
89 36.770°N 80.001°W 0.0036 0.1944
104 40.477°N 79.187°W 0.0036 0.1944
119 40.401°N 80.096°W 0.0036 0.1944
9 38.906°N 75.513°W 0.0054 0.2916
51 40.371°N 77.402°W 0.0054 0.2916
114 39.860°N 79.229°W 0.0054 0.2916
31 41.402°N 78.024°W 0.0072 0.3888
42 41.357°N 76.535°W 0.0072 0.3888
46 40.613°N 78.141°W 0.0090 0.4860
58 39.504°N 76.885°W 0.0090 0.4860
15 39.250°N 75.861°W 0.0108 0.5832
21 41.707°N 76.485°W 0.0108 0.5832
26 41.059°N 76.094°W 0.0108 0.5832
29 40.972°N 78.406°W 0.0108 0.5832
77 37.531°N 79.679°W 0.0108 0.5832
88 36.781°N 80.025°W 0.0108 0.5832
11 38.229°N 75.471°W 0.0126 0.6804
18 41.791°N 77.015°W 0.0126 0.6804
22 41.558°N 75.895°W 0.0126 0.6804
101 40.286°N 78.921°W 0.0126 0.6804
106 40.293°N 79.341°W 0.0126 0.6804
126 40.628°N 80.338°W 0.0126 0.6804
56 39.371°N 76.446°W 0.0144 0.7776
63 38.335°N 79.239°W 0.0144 0.7776
76 38.195°N 79.570°W 0.0144 0.7776
110 39.980°N 79.764°W 0.0144 0.7776
8 39.164°N 75.519°W 0.0162 0.8748
65 38.637°N 78.853°W 0.0162 0.8748
99 40.836°N 79.110°W 0.0162 0.8748
27 41.078°N 76.431°W 0.0180 0.9720
116 39.828°N 79.373°W 0.0180 0.9720
17 39.657°N 75.822°W 0.0198 1.0692
28 40.897°N 78.677°W 0.0198 1.0692
109 39.759°N 79.971°W 0.0198 1.0692
34 40.890°N 77.794°W 0.0216 1.1664
111 39.422°N 79.424°W 0.0216 1.1664
55 39.604°N 76.620°W 0.0234 1.2636
40 41.418°N 77.033°W 0.0252 1.3608
66 39.612°N 77.237°W 0.0252 1.3608
68 38.960°N 76.926°W 0.0252 1.3608
90 41.938°N 79.133°W 0.0252 1.3608
117 40.018°N 79.593°W 0.0252 1.3608
41 41.325°N 76.912°W 0.0270 1.4580
49 40.216°N 78.265°W 0.0288 1.5552
108 40.716°N 79.699°W 0.0288 1.5552
113 39.702°N 79.136°W 0.0288 1.5552
23 41.680°N 75.472°W 0.0306 1.6524
96 41.193°N 79.440°W 0.0306 1.6524
94 41.575°N 78.692°W 0.0324 1.7496
48 40.072°N 78.493°W 0.0342 1.8468
93 41.631°N 78.577°W 0.0342 1.8468
123 40.817°N 80.242°W 0.0360 1.9440
10 38.389°N 75.324°W 0.0378 2.0412
54 40.050°N 76.277°W 0.0378 2.0412
59 39.238°N 77.056°W 0.0378 2.0412
112 39.654°N 79.408°W 0.0378 2.0412
124 40.884°N 80.234°W 0.0378 2.0412
127 36.939°N 80.887°W 0.0378 2.0412
2 39.869°N 75.408°W 0.0396 2.1384
6 40.073°N 75.861°W 0.0396 2.1384
45 40.684°N 78.234°W 0.0396 2.1384
102 40.346°N 78.883°W 0.0396 2.1384
43 40.867°N 77.048°W 0.0414 2.2356
78 37.797°N 78.491°W 0.0414 2.2356
121 41.422°N 80.376°W 0.0414 2.2356
50 40.213°N 77.925°W 0.0450 2.4300
52 40.323°N 77.169°W 0.0450 2.4300
16 39.280°N 76.015°W 0.0468 2.5272
128 37.207°N 82.296°W 0.0468 2.5272
67 38.976°N 77.246°W 0.0486 2.6244
69 38.952°N 76.966°W 0.0486 2.6244
72 38.242°N 76.504°W 0.0486 2.6244
79 37.671°N 78.086°W 0.0486 2.6244
85 37.258°N 79.939°W 0.0504 2.7216
57 39.593°N 76.968°W 0.0522 2.8188
75 37.884°N 77.165°W 0.0522 2.8188
91 41.853°N 79.317°W 0.0522 2.8188
19 41.908°N 77.129°W 0.0540 2.9160
47 40.485°N 78.019°W 0.0540 2.9160
98 40.939°N 79.008°W 0.0558 3.0132
1 40.434°N 75.117°W 0.0576 3.1104
71 38.587°N 77.429°W 0.0576 3.1104
120 41.498°N 80.460°W 0.0576 3.1104
129 36.897°N 81.746°W 0.0576 3.1104
92 41.482°N 79.695°W 0.0648 3.4992
62 39.175°N 78.078°W 0.0684 3.6936
70 38.813°N 77.228°W 0.0684 3.6936
20 41.997°N 77.140°W 0.0702 3.7908
14 38.997°N 75.786°W 0.0720 3.8880
64 38.323°N 78.755°W 0.0774 4.1796
86 37.105°N 79.295°W 0.0792 4.2768
87 36.915°N 78.741°W 0.0828 4.4712
84 36.717°N 77.832°W 0.0864 4.6656
73 38.308°N 77.529°W 0.0954 5.1516
83 36.763°N 76.898°W 0.0972 5.2488
74 37.768°N 77.332°W 0.1008 5.4432
82 36.770°N 77.166°W 0.1044 5.6376
7 39.366°N 75.669°W 0.1224 6.6096
81 37.436°N 77.061°W 0.1458 7.8732
Figure 2

Key Points

  • From 1960 through 2014, water temperature increased at 79 percent of the stream sites measured in the Chesapeake Bay region (see Figure 1). More than half of these increases were statistically significant. Only 5 percent of stations had a significant temperature decrease over the same period.
  • Since 1960, the Chesapeake Bay region has experienced an overall increase in stream water temperature. Temperature has risen by an average of 1.2°F across all sites and 2.2°F at the sites where trends were statistically significant.
  • Stream temperatures have risen throughout the Chesapeake Bay region. The largest increases have occurred in the southern part of the region.

Background

Water temperature is an important physical property of every river and stream. Many plants, animals, and other organisms living in streams can flourish only in a specific range of water temperatures. Temperature can affect certain aspects of water quality. For example, higher temperatures reduce levels of dissolved oxygen in the water, which can negatively affect the growth and productivity of aquatic life. Persistently warmer temperatures in streams can accelerate natural chemical reactions and release excess nutrients into the water.1 A stream’s water temperature can also influence the circulation or mixing patterns in the water it flows into, like bays and estuaries, potentially affecting nutrient levels and salinity.

Temperatures can vary naturally along the length of a stream, from cold temperatures near a source of meltwater to higher temperatures near its outlet to the sea. The temperature at any given point is a product of many different factors, including sources of water (for example, melted snow, a recent rainstorm, or groundwater), the amount of water in the stream (streamflow), air temperature, plants along the bank (for example, trees that provide shade), and the amount of development within the watershed. Over time, however, an area’s climate has the strongest natural influence on a stream’s temperature.

The Chesapeake Bay is the largest estuary in the United States, an important habitat for countless aquatic species, and a driver of the regional economy. As rising air temperatures (see the U.S. and Global Temperature indicator) cause stream temperatures to rise, warmer stream water coming into the bay can stress plants and animals and worsen the effects of nutrient pollution that the bay is already facing.2

About the Indicator

The U.S. Geological Survey maintains thousands of stream gauges across the United States. Each gauge measures water levels several times a day, typically every 15 minutes. Field technicians visit each gauging station an average of eight times a year to measure various stream conditions, including water temperature. This indicator shows how average water temperatures throughout the year changed between 1960 and 2014 at 129 stream gauges located across the Chesapeake Bay region. These stations were selected because they had high-quality data for this entire time period.

About the Data

Indicator Notes

In addition to climate, changes to a stream’s average water temperature can be influenced by other factors such as industrial discharges, changes to local hydrology (such as construction and operation of dams and channels), and changes to land cover in the watershed. This indicator uses measurements from all stream gauges with sufficient data. Thus, it includes some stream sites that are likely more disturbed by human activities than others. A more detailed analysis of this data set found that water temperature tends to increase more quickly than air temperature in agricultural areas without major dams, but more slowly at forested sites and in areas influenced by dams.4 Nonetheless, a comparison of 35 relatively undisturbed reference stations with the remaining 94 stations in this indicator showed no significant difference in trends between the two groups of stations.5

This indicator is based on measurements that are collected an average of eight times per year, but more in some years and less in others. The data were analyzed in a way that accounts for variations in timing and makes it possible to compare average temperatures across many years.

Data Sources

This indicator is based on an analysis developed by the U.S. Geological Survey (USGS).6 Periodic temperature data were collected by the USGS, and these data are stored in the USGS National Water Information System.

Technical Documentation

References

  1. Duan, S.W., and S.S. Kaushal. 2013. Warming increases carbon and nutrient fluxes from sediments in streams across land use. Biogeosciences 10:1193–1207.
  2. Duan, S.W., and S.S. Kaushal. 2013. Warming increases carbon and nutrient fluxes from sediments in streams across land use. Biogeosciences 10:1193–1207.
  3. Jastram, J.D., and K.C. Rice. 2015. Air- and stream-water-temperature trends in the Chesapeake Bay region, 1960–2014. U.S. Geological Survey Open-File Report 2015-1207. https://pubs.er.usgs.gov/publication/ofr20151207.
  4. Rice, K.C., and J.D. Jastram. 2015. Rising air and stream-water temperatures in Chesapeake Bay region, USA. Climatic Change 128(1):127–138.
  5. Jastram, J.D., and K.C. Rice. 2015. Air- and stream-water-temperature trends in the Chesapeake Bay region, 1960–2014. U.S. Geological Survey Open-File Report 2015-1207. https://pubs.er.usgs.gov/publication/ofr20151207.
  6. Rice, K.C., and J.D. Jastram. 2015. Rising air and stream-water temperatures in Chesapeake Bay region, USA. Climatic Change 128(1):127–138.

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 by the build-indicator skill. Data, chart code, and the full extraction pipeline are maintained in the stream-temperature repository, which this page reads its data from directly.

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