Methodology & Data Sources

Your FireRisk is a transparent weighted blend of four independent federal datasets, each pulled live for your exact coordinates. Every factor is a real measurement — we do not derive multiple factors from one dataset, we exclude inputs that are merely correlated proxies of another, and we do not invent numbers for things a remote model can’t see. The scale is consistent across all states, so a 60 in Colorado means the same as a 60 in California.

What we deliberately do not put in the score

Two of the biggest drivers of whether a home survives a wildfire — its defensible space and its structure hardening (roof, vents, deck, siding) — cannot be measured remotely from any satellite or federal raster. Earlier versions of many risk tools (and ours) showed an assumed “baseline” number for these. We removed that: presenting an assumption as a measurement is the opposite of trustworthy. Instead, those home-specific factors are scored by the free mitigation plan generator, where you answer for your actual home. Your FireRisk reflects the location’s hazard; the planner reflects the home’s readiness. You need both.

Every data source, dated and cited

Regulatory vs. advisory — and resolution

Most wildfire data — including the federal USFS and FEMA layers — are advisory models, not legal designations. The one binding exception we surface is California's CAL FIRE Fire Hazard Severity Zone, which legally drives building codes, defensible-space law, and seller disclosure. We label which is which on every report.

National layers are raster datasets (30–270 m), so they describe the area around your home, not the parcel alone. Your address determines which cells are sampled, but true parcel-level risk also depends on your specific structure and defensible space — which is why the report recommends an on-site assessment for High and Very High results.

What “Risk to Structures” actually decomposes into

Our heaviest-weighted input, USFS Risk to Potential Structures (RPS), is not a vague index — it is, by definition, annual burn probability × conditional risk to a structure, where conditional risk combines modeled fire intensity (flame length) with a structure’s susceptibility response function. In other words it already integrates the two questions a wildfire scientist asks — how likely is fire here and how bad would it be — into one number, computed nationally at 30 m on one consistent method. The USFS publishes its components (Burn Probability, Conditional Flame Length, Conditional RPS) as separate layers; we deliberately score the integrated RPS rather than re-combining its parts, to avoid double-counting.

Validation & scientific basis

Every input traces to peer-reviewed federal science. The risk layer (USFS Wildfire Risk to Communities — Risk to Potential Structures) is built on the Rocky Mountain Research Station's FSim large-fire simulation system (Finney et al.), LANDFIRE fuels, and the Wildfire Risk to Communities methodology (Scott, Dillon, et al.) — the same models used in federal wildfire planning and the National Cohesive Wildland Fire Management Strategy. Fire history is the official NIFC InterAgency Fire Perimeter record (2000–2024); the county layer is FEMA's National Risk Index wildfire risk score; slope is USGS 3DEP. We add no proprietary “secret sauce” on top — the score is a transparent, reproducible weighting of these public datasets, and we publish the exact formula and the raw values (including your RPS) so any expert can audit it.

FireRisk is provided for informational purposes. Risk scores and savings figures are estimates, not guarantees of insurability, premium, or grant approval. Verify any regulatory designation with your local fire authority before construction or sale.