Understanding patterns in the numbers and causes of wildfire ignitions

This collection of research leverages a comprehensive dataset of wildfires spanning recent decades to examine patterns of and trends in ignitions across the western United States. Human-caused ignitions account for over 60% of all recorded wildfires across the western U.S. and are responsible for the vast majority of wildfire-related societal impacts, underscoring the value of effective wildfire prevention and risk-mitigation strategies. 

Although wildfire prevention and mitigation efforts have decreased the overall number of wildfires, environmental conditions have promoted larger fire sizes. While daily wildfire ignition probabilities generally track weather patterns, they can remain persistently high in areas where human factors dominate. 

The data supporting these analyses come from the final fire reporting systems of the federal, state, and local fire services, providing the most comprehensive picture of wildfire activity over recent decades (1992-2020). The data were carefully filtered for this research to remove reporting artifacts, which can make it difficult to detect true changes in ignition patterns. The date and ignition point of each fire was used to associate potential explanatory information related to biophysical factors, population, and firefighting resource availability.