Coldest Days Warming Up

Since 1970, the coldest day of the year has warmed by an average of 7°F across 242 U.S. locations, with 97% of locations seeing a rise of at least 1°F. Winter cold snaps have also become shorter, decreasing by an average of six days in 97% of 244 analyzed locations. The most significant warming of coldest days occurred in the Ohio Valley (8.7°F) and Northwest (8.4°F) regions, with the highest individual increases recorded in Boise, Idaho (15.7°F) and Las Vegas, Nevada (14.3°F). These trends contribute to longer allergy and growing seasons, disrupted crop chill requirements, and altered water supplies.

• Between 1970 and 2023, the annual coldest temperatures across 242 analyzed U.S. locations increased by an average of 7°F. The vast majority of these locations (97%) saw a rise of at least 1°F, and 74% experienced an increase of at least 5°F.
• Regional analysis shows that every U.S. climate region had an average increase of at least 4.6°F in yearly coldest temperatures since 1970. The highest average increases were found in the Ohio Valley at 8.7°F and the Northwest at 8.4°F.
• Specific U.S. cities recorded the highest increases in coldest temperatures since 1970, led by Boise, Idaho (15.7°F), followed by Las Vegas, Nevada (14.3°F), Idaho Falls, Idaho (14.3°F), and Reno, Nevada (14°F).
• Winter cold snaps in the U.S. have become shorter and less frequent. From 1970 to 2021, cold snaps shortened by an average of six days in 97% of 244 analyzed locations.
• The warming of the coldest time of year has various ecological and societal impacts, including longer growing and allergy seasons, disruption of chill requirements for fruit and nut crops, changes to snowfall and water supplies, and an increase in mosquito days.

APA

Climate Central (2024). Coldest Days Warming Up. https://www.climatecentral.org/climate-matters/coldest-days-warming-up

Chicago

Climate Central. Coldest Days Warming Up. 2024. https://www.climatecentral.org/climate-matters/coldest-days-warming-up.

Wikipedia

{{cite report |author=Climate Central |title=Coldest Days Warming Up |date=24 January 2024 |url=https://www.climatecentral.org/climate-matters/coldest-days-warming-up |access-date=23 October 2026 |via=Climate Insights Directory}}

BibTeX

@techreport{climatecentral2024coldest, author = {{Climate Central}}, title = {{Coldest Days Warming Up}}, institution = {Climate Central}, year = {2024}, month = jan, url = {https://www.climatecentral.org/climate-matters/coldest-days-warming-up}, urldate = {2026-10-23}, note = {Indexed by Climate Insights Directory} }