How fireriskhere.com works
Data sources
- Wildland–Urban Interface (WUI). SILVIS Lab WUI 1990–2020, University of Wisconsin–Madison, published through the USDA Forest Service. This site uses the 2020 classification (the
WUICLASS2020field). silvis.forest.wisc.edu - California fire hazard — State Responsibility Area (SRA). CAL FIRE Fire Hazard Severity Zones in the SRA, effective April 1, 2024. osfm.fire.ca.gov
- California fire hazard — Local Responsibility Area (LRA). CAL FIRE recommended Fire Hazard Severity Zones in the LRA, recommended March 24, 2025. osfm.fire.ca.gov
- Active fires. NIFC Wildland Fire Interagency Geospatial Services (WFIGS) “Current” wildland fire incident locations, refreshed every 15 minutes. data-nifc.opendata.arcgis.com
Methodology
- Risk classifications are aggregated to a 1 km grid. Where more than one designation overlaps a cell, the cell reports the most severe one — a conservative-burn rule.
- In California, CAL FIRE Fire Hazard Severity Zone severity takes precedence over the SILVIS WUI classification wherever a zone is present. SILVIS WUI is used everywhere else, and as the fallback for California locations that no CAL FIRE zone covers.
- “Active fires” are incidents in NIFC’s Current lifecycle, which includes both actively burning fires and fires that are contained but not yet declared out.
- The 50-mile figure counts those incidents within 50 statute miles of the visitor’s IP-derived coordinates, measured as great-circle (haversine) distance.
Limitations
- IP geolocation is approximately city-level — typically accurate to within tens of kilometers. The 1 km grid is finer than that, so a single cell aggregates across multiple parcels and the located point may differ from a specific address.
- A cell that straddles two severity zones reports the more severe of the two.
- CAL FIRE “NonWildland” designations are not treated as a hazard class; those locations fall through to the SILVIS WUI underlay.
- WFIGS incident data reflects the federal source feed as published. This site selects wildfire incidents (not prescribed burns) but applies no further quality filtering or correction.
- This site presents data for informational purposes. It is not advice. For evacuation or insurance decisions, consult local fire authorities.
Why our numbers may differ from official agencies
Our active-fire count refreshes every 15 minutes, so an incident reported in the last few minutes may not appear here yet. Locations come from the visitor’s IP address — approximately city-level — and the hazard classification is sampled from a 1 km grid. Both can place a visitor in a slightly different cell than a parcel-level lookup would, especially near zone boundaries. For evacuation, road-closure, and emergency orders, official county and state sources are authoritative.
The map overlay
The map on the home page and on the national map includes a toggle that overlays one of two fire-risk classifications on top of the base tiles. The toggle has three states — Off (the default), WUI, and FRAP — and the two overlays are mutually exclusive. The toggle remembers the last selection on the same device.
- WUI shows the SILVIS Wildland–Urban Interface classification across the contiguous United States. Cells classified as Interface or Intermix are colored; cells with no WUI designation render transparent so the base map shows through.
- FRAP shows the CAL FIRE Fire Hazard Severity Zone classification, colored by severity (Moderate, High, Very High). It is available only in California — there is no federal equivalent that grades fire-hazard severity at the same granularity outside the state, so the FRAP option is hidden for visitors outside California rather than shown as empty.
The overlay tiles are rendered from the same 1 km raster grids described under Methodology above, and inherit the same precision caveat: one overlay cell covers roughly a square kilometer on the ground, which is finer than IP geolocation can place a visitor but coarser than a parcel boundary.