Fire weather: Heat, dryness, and wind are driving wildfires in the Western U.S.

To explore changes in weather conditions that increase the spread of fire, Climate Central analyzed data from weather stations in 225 locations across 17 states going back to 1973. This review of historical trends in fire weather—a combination of high heat, low humidity, and strong winds—aims to investigate how climate change is affecting wildfire risk throughout the American West.

Climate change is worsening wildfires across forested land and lengthening wildfire seasons in the Western United States. Warming from heat-trapping pollution is drying out forests, grasslands and other landscapes, increasing the likelihood that destructive fires will erupt and spread. And warming is also affecting day-to-day weather in ways that this analysis shows are increasing the frequency of fire weather days.