Facts + Statistics: Wildfires

Wildland fires

As many as 90 percent of wildland fires in the United States are caused by people, according to the U.S. Department of Interior. Some human-caused fires result from campfires left unattended, the burning of debris, downed power lines, negligently discarded cigarettes and intentional acts of arson. The remaining 10 percent are started by lightning or lava.

According to Verisk’s 2019 Wildfire Risk Analysis 4.5 million U.S. homes were identified at high or extreme risk of wildfire. According to latest Verisk estimates, in California, there were more than 2 million properties at high to extreme wildfire risk in 2021, the largest number of properties of any U.S. state. (See chart: States At High To Extreme Wildfire Risk, 2021, below.)

Annual Number of Acres Burned in Wildland Fires, 1980-2021

 

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*2004 fires and acres do not include state lands for North Carolina.

Source: National Interagency Fire Center.

View Archived Graphs

FireLine®, Verisk’s wildfire risk management tool, assesses wildfire risk at the address level using advanced remote sensing and digital mapping technology. The three primary factors considered in analyzing wildfire risk are distribution of vegetative fuel, steepness of slope and degree of access for firefighting equipment. FireLine assigns a wildfire hazard score for each factor plus a cumulative score, on a scale from negligible to extreme risk. The following chart ranks the most wildfire-prone western U.S. states by high to extreme wildfire risk as of 2021. According to Verisk estimates, in California, there were more than 2 million properties at high to extreme wildfire risk in 2021, the largest number of properties of any U.S. state.