Climate Change Indicators in the United States
Temperatures are rising, snow and rainfall patterns are shifting, and more extreme climate events – like heavy rainstorms and record high temperatures – are becoming more common. Many of these observed climate changes are linked to rising levels of greenhouse gases in our atmosphere, caused by human activities. EPA’s indicators provide evidence of these changes and their impacts on people and the environment. EPA partners with dozens of data contributors to compile and keep these indicators up to date.
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View the Indicators
Check out more than 50 indicators that show the causes and effects of climate change.
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Dig into the Data
Explore the data with maps and figures.
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Indicator Stories
Follow along with detailed narratives and supporting data about specific effects of climate change.
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About the Indicators
Learn about how EPA develops indicators, find answers to frequent questions, and access publications.
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Warmer spring.
The average spring temperature across the contiguous United States has increased by about 2°F since 1896. This warming shifts the timing of spring events in the physical environment (such as snow and ice melting), for plants (leaf growth, flower bloom, and the start of allergy season) and for animals (emergence from hibernation, migration, and breeding—including insect pests). These changes can affect water supply, agriculture, seasonal recreation and tourism, and public health. Learn more in the Seasonal Temperature indicator. -
Earlier ice breakup in Alaskan rivers.
For more than a century, local citizens have held contests to guess when the ice on the Tanana, Yukon, and Kuskokwin rivers will start to break up and move each spring. The resulting records show that all three rivers have been breaking up earlier. Beyond the friendly competition, ice breakup in these Alaskan rivers is important as early thawing can cause severe ice movement, jamming, infrastructure damage, and floods that affect transportation and subsistence ways of life. See more details about the Ice Breakup in Three Alaskan Rivers. -
Reduced snowpack.
Snowpack is the amount of snow that accumulates on the ground. Snowpack is particularly important to communities in the western United States as it stores water in the winter and provides water for hydropower, irrigation, and drinking as it melts in the spring and summer. Warmer winters are causing snowpack to decline throughout the West, threatening recreation and tourism in the winter months and water availability in the warmer, drier months. Explore the Snowpack indicator to learn about these changes and their impacts. -
Earlier leaf and bloom dates.
Warmer weather in the winter and earlier arrival of springlike temperatures can trigger leaves to sprout and flowers to bloom earlier than usual. These events are easy to observe and widely tracked, thanks to thousands of “community scientists” across the country who report local observations every year. That makes leaf and bloom dates a valuable indicator for the overall timing of spring events. Earlier leaf and bloom dates result in longer growing seasons, which may benefit some farmers and crops. But others end up dealing with increased pests and invasive species, higher demand for irrigation, and longer allergy seasons. Explore trends near you in the Leaf and Bloom Dates indicator.