2025 United States wildfires

Season background

While most wildfires in the United States occur from May to November, wildfires can occur during any time of the year. Peak fire season is normally in August, when it is the hottest and driest. Wildfires outside of the fire season are becoming more common from climate change and changing weather patterns. Rising temperatures are leading to earlier snowmelt and later fall and winter precipitation. Drought and hot, dry weather events are becoming more common. Forests pests, such as bark beetles, and invasive species, such as cheatgrass, kill trees and make forests more vulnerable. Areas with dense vegetation or tree cover provide ample fire fuel.^[3]

Wildfire season is expected to worsen from climate change. Warmer, drier conditions are expected to increase fire severity in California and the Southwest.^[3]

Seasonal forecasts

In March 2025, the Climate Prediction Center (CPC), a branch of NOAA, issued its National Seasonal Fire Outlook. This forecast projected above-normal wildfire risk for much of California, Oregon, Washington, Nevada, and the southwestern United States. The elevated risk was linked primarily to persistent atmospheric patterns resembling La Niña, which typically reduce precipitation and increase temperatures in these regions. The outlook considered factors such as expected temperature and precipitation anomalies, soil moisture, and vegetation dryness to predict fire activity for the upcoming season.^[4]

Climatic conditions

United States drought at the start of water year.

During spring and early summer 2025, observed temperature anomalies across the western U.S. averaged approximately +1.5°C above the 30-year climatological norm. These warmer-than-average conditions contributed to earlier snowmelt and accelerated drying of live and dead vegetation, factors known to increase wildfire potential. These temperature trends aligned with the CPC's seasonal forecast and contributed to extending the typical wildfire season window.^[5]

By mid-2025, the U.S. Drought Monitor reported that nearly 45% of the western United States was under severe to exceptional drought conditions, with California and Nevada among the hardest-hit states. These drought conditions stressed vegetation and depleted soil moisture, significantly reducing fuel moisture content and thereby increasing wildfire risk and severity across large areas.^[6]

Throughout the season, live fuel moisture levels dropped below 70%, and dead fuel moisture fell below 5% in many fire-prone ecosystems. These critically low moisture levels meant vegetation was highly flammable, facilitating rapid wildfire ignition and spread. Fire Danger Ratings issued by the National Interagency Fire Center (NIFC) frequently reached "High" to "Extreme" during peak fire months, driven by hot, dry winds and low relative humidity. Enhancements in fire monitoring technology were seen in 2025 with the operational deployment of the GOES-T satellite system, which provided real-time thermal imagery to aid in wildfire detection and management.^[7][8][9]