More Extreme Heat in National Parks

The 25 most-visited national parks in the contiguous U.S. are projected to see a nearly five-fold increase in extremely hot days per year by 2050 under a 'warm wet' scenario, and up to a ten-fold increase under a 'hot dry' scenario. These trends, combined with record-breaking visitation, increase the risk of heat-related illnesses for visitors and threaten biodiversity and infrastructure. The National Park Service is implementing adaptation strategies, such as the Climate Change Response Strategy, to mitigate these risks.

• The combined area of the National Park System warmed twice as fast as the overall United States between 1895 and 2010, largely because many parks are in climate-sensitive environments like the Arctic, mountains, and arid regions.
• By 2050, the 25 most-visited national parks in the contiguous U.S. are projected to experience nearly five times more extremely hot days annually compared to the 1979-2012 period under a 'warm wet' scenario, with an increase of between six and 22 days per year.
• Under a 'hot dry' scenario, which represents the upper end of projected warming, the 25 most-visited parks could see a ten-fold increase in the annual frequency of extremely hot days by 2050.
• Yosemite National Park is expected to see the largest increase among the 25 most-visited parks, rising from four extremely hot days per year (1979-2012) to 26 days by 2050. Great Smoky Mountains National Park is projected to increase from three days to 23 days annually.
• Six of the 25 most-visited parks have extreme heat thresholds exceeding 100°F: Badlands, Arches, Grand Canyon, Joshua Tree, Canyonlands, and Hot Springs. These sites are projected to see a 3-fold to 6-fold increase in such days by 2050.
• Climate change is increasing heat-related health risks for visitors, particularly during shoulder seasons (spring and fall) when extreme heat is unexpected. This is compounded by the fact that visitation is expected to increase and the visitation season to lengthen by 2050.
• Human-caused climate change has already led to documented impacts in specific parks, including the loss of bird species in Death Valley, increased tree mortality in Sequoia, melting glaciers in Glacier Bay, and expanded wildfire-burned areas in Yosemite.

APA

Climate Central (2025). More Extreme Heat in National Parks. https://www.climatecentral.org/climate-matters/more-extreme-heat-in-national-parks

Chicago

Climate Central. More Extreme Heat in National Parks. 2025. https://www.climatecentral.org/climate-matters/more-extreme-heat-in-national-parks.

Wikipedia

{{cite report |author=Climate Central |title=More Extreme Heat in National Parks |date=9 April 2025 |url=https://www.climatecentral.org/climate-matters/more-extreme-heat-in-national-parks |access-date=23 October 2026 |via=Climate Insights Directory}}

BibTeX

@techreport{climatecentral2025more, author = {{Climate Central}}, title = {{More Extreme Heat in National Parks}}, institution = {Climate Central}, year = {2025}, month = apr, url = {https://www.climatecentral.org/climate-matters/more-extreme-heat-in-national-parks}, urldate = {2026-10-23}, note = {Indexed by Climate Insights Directory} }