CONFEX: A Database for CONUS Fire EXtent

Abstract. This article presents the CONUS Fire EXtent (CONFEX) database. CONFEX is based on the VIIRS S-NPP 375 m active fire product and provides wildfire perimeters, centroids, ignition locations, and start and end dates for 2012–2024 across CONUS and Alaska. The algorithm extracts hotspot detections from VIIRS S-NPP, clusters them into fire events using a spatio-temporal DBSCAN approach and derives a perimeter polygon and centroid for each event, assigning event-level attributes. When evaluated against MTBS using regional area-threshold filters, the algorithm obtained area-based F1 scores of 67 % (western CONUS; >1000 acres), 77 % (Alaska; >1000 acres), and 26 % (eastern CONUS; >500 acres); and when evaluated against California FRAP (excluding the 2020 tuning year), an area-based F1 of 69 % was found, demonstrating the ability to aggregate VIIRS hotspots into spatially and temporally coherent fire events.  To our knowledge, CONFEX is the first publicly available, moderately high-resolution wildfire-extent dataset developed for the CONUS and Alaska regions using the VIIRS S-NPP 375 m active fire product. The database provides a valuable resource for researchers to study fire regimes in CONUS and Alaska.