Extreme Weather Toolkit: Snow & Ice

The timing, location, and amount of snowfall is shifting across the U.S. 

The frozen parts of Earth’s surface — including ice sheets, glaciers, sea ice, permafrost, and snow cover — have shrunk over recent decades due to human-caused warming. 

Snow keeps our planet cooler, makes up more than 50% of the water supply in the western U.S., and supports ecosystems, economies and cultures across the nation. 

Our warming atmosphere holds about 4% more moisture per 1°F of temperature rise. As winters warm, more of that extra moisture now falls as rain instead of snow at about 80% of 177 weather stations across the contiguous U.S. 

From 1970 to 2023, annual snowfall decreased at 64% of 2,041 monitoring stations across the contiguous U.S. 

Decades of shrinking snowpack has reduced snow-derived freshwater in the western U.S. by 15-30% since 1955. These trends could continue, with an additional 25% decline in snow-derived freshwater expected by 2050.

The latest IPCC reports conclude with near certainty that Northern Hemisphere snow cover extent and duration will continue to decrease as our climate continues to warm.

Climate models suggest that Northern Hemisphere snow cover will decrease at a rate of -8% per 1.8°F (1°C) of global surface air warming. 

Updated: April 2024

Resources

These resources explore the science, trends, and local impacts of snow & ice in the U.S.

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Climate Matters

Snowfall Trends

Snow keeps our planet cooler, feeds water supplies, and underpins regional economies and cultures. Here’s how snow is changing across the U.S. with our warming climate.

Climate Matters

Warm Winter Days Boosted by Climate Change in U.S. Cities

Carbon pollution drove abnormal warmth this winter in cities across the U.S. — especially in the Midwest and Great Plains.

Climate Matters

Great Lakes Ice

Over the last five decades, the Great Lakes have trended toward less ice, for less time — consistent with global trends in lake ice decline as the planet warms.

Climate Matters

Shifting Snow in the Warming U.S.

Snow keeps our planet cooler, feeds water supplies, and underpins local economies and cultures. We unpack how climate change is affecting snow—and snow-dependent communities—across the U.S.

Climate Matters

Atmospheric Rivers

Atmospheric rivers bring both vital water resources and deadly hazards—especially in the western U.S.

Climate Matters

Water in the West

This week, we explain how exceptional drought and our warming climate put western water supplies at risk.