Climate Change and U.S. Weather

A new Climate Central analysis finds that winters, defined by temperature rather than the calendar, have shortened in 80% of 245 U.S. cities when comparing 1998–2025 to 1970–1997, even as this year has delivered brutal cold and snow in many regions. Researchers defined 'winter' as the coldest consecutive 90-day period in the earlier baseline and then measured how often those historically wintry temperatures occur today, concluding that in 195 affected cities the season now lasts an average of nine fewer days. The biggest contractions are in Alaska, where Juneau’s winter has shrunk by 62 days and Anchorage’s by 49, and in the continental U.S. where Miami’s winter has shortened by 38 days, consistent with rapid warming at high latitudes and in subtropical zones. A few locations, especially along California’s coast, show the opposite pattern, with temperature-defined winters in Eureka and Monterey now 50 and 46 days longer, even as the broader West struggles with a snow drought that threatens tourism and water supplies. The findings reinforce what other climate records have shown: average warming is shifting the timing and intensity of cold seasons in ways that will ripple through heating demand, ecosystems, agriculture, and regional economies despite year-to-year weather swings.