The Western United States MTBS-Interagency Database of Large Wildfires, 1984–2024 (WUMI2024a)

This Western US MTBS-Interagency database (WUMI) of wildfires covers the period 1984–2024 and the geographic domain of the 11 westernmost states in the contiguous US. This is an update of a previous WUMI verson of the WUMI, so here has the version number 2024a. The previous version can be found at https://doi.org/10.5061/dryad.sf7m0cg72. The WUMI2024a represents 21,940 wildfires ≥1 km2 in size, or 22,234 if fire complexes are disaggregated into their constituents. We compile the WUMI2024a by merging seven government databases and quality controlling by identifying and removing duplicate occurrences of fires. An important feature of this database is that it includes fire perimeters and 1-km resolution maps of the areas burned within. For more than 10,300 wildfires, the map of area burned is based on 30-m satellite data and accounts for unburned areas within fire boundaries. The fire perimeters and burn maps aid assessment of the landcover types that burn and can be used to improve simulations of how historical fires have affected ecosystems and smoke emissions. The WUMI2024a can be quickly updated as new and improved data become available and can thus be used to monitor trends, assess the historical context of extreme events, and update statistical analyses of the drivers and effects of western US wildfire in near real-time.