Fire Hazard Severity Zone (FHSZ)
A Fire Hazard Severity Zone is the State of California's own rating of how hazardous a piece of land is for wildfire. CAL FIRE maps the whole state and assigns each area Moderate, High or Very High. The rating describes the hazard of the land — fuel, slope, weather — rather than the condition of any particular house on it.
Two maps exist side by side. State Responsibility Area (SRA) covers land where the state is responsible for wildfire protection, largely unincorporated and wildland. Local Responsibility Area (LRA) covers land protected by a city or county fire department. A property sits in one or the other, and both carry zone ratings.
CAL FIRE zones describe mapped hazard. Insurers use their own wildfire risk models to make underwriting and pricing decisions; this map does not reproduce those models. It is not a score of your house: a well-prepared home and a neglected one on the same street sit in the same zone.
Zone boundaries do not follow parcel lines, so neighbouring properties can fall in different zones. That is why an address-level check is worth doing rather than reasoning from the town or county.
Related terms
- Safer from Wildfires — The California regulation listing the mitigation measures insurers must recognise.
- Defensible space — The managed area around a structure that slows a fire and gives crews room to work.