Mapping wildfire risk across the US, day by day

Wildfire risk mapping across the U.S. and surrounding regions, day by day, aims to help firefighters and authorities better prepare for and contain blazes. Scientists at the U.S. National Science Foundation's National Center for Atmospheric Research (NSF NCAR) are developing real-time maps of vegetation moisture, which are updated hourly or daily depending on the location. These maps account for both living and dead vegetation, or 'fuel,' providing vital information on wildfire spread potential.

The maps, accessible via an NSF NCAR webpage, show high wildfire risk areas, primarily in Southern California, Nevada, Arizona, as well as moderate risk in the Southeast and upper Midwest. The maps use advanced weather models and observations from satellites such as the VIIRS (Visible Infrared Imaging Radiometer Suites) and ABI (Advanced Baseline Imager) from NASA and NOAA.

Machine learning algorithms process this data to estimate vegetation moisture content at a resolution of 375 meters across the contiguous U.S. and Alaska, and 750 meters in Hawaii.

In 2023, the research team expanded the maps' capabilities to provide separate moisture estimates for trees, shrubs, and grasses. This distinction is crucial because different plant types have varying moisture retention and drying rates, which directly impact wildfire behavior. Pedro Jimenez Munoz, an NSF NCAR scientist leading the research, emphasizes that accurately mapping fuel moisture content is key to modeling wildfires and identifying at-risk regions and spread rates.

For instance, a September 20, 2026 map revealed especially dry small dead fuels in parts of Southern California, Nevada, and Arizona, underscoring the map's utility in pinpointing high-risk zones. With these detailed, daily updates, the maps serve as a critical tool for wildfire preparedness and response across the U.S. and Canada.