Methodology

Fire hazard severity zones

CAL FIRE Office of the State Fire Marshal

CAL FIRE sorts land into three hazard classes. Each zone is a polygon covering an area, not a rating attached to a parcel or a building.

• Non-wildland Unzoned Land with no fuel model: urban, agricultural and barren land, and water or wetlands. It is scored by its proximity to wildland rather than by what grows on it. It appears in the local data only, and the map leaves it unshaded.
• Moderate FHSZ 1 The lowest of the three mapped classes. Moderate is not the same as no hazard.
• High FHSZ 2 Conditions that support fire spread more readily than surrounding moderate ground.
• Very High FHSZ 3 The most hazardous class, and the one carrying the heaviest obligations: ignition-resistant construction under Chapter 7A for new building, defensible space, and disclosure when a property is sold.

Hazard is not risk

This is the distinction that matters most, and the one the word "zone" tends to obscure. Hazard describes the long-run physical conditions of a landscape: what grows there, how steep it is, how it burns and how far embers travel when it does. It is a statement about the ground over decades, not a forecast for this season.

Risk is a different question. It asks what would actually happen to a particular building, and so it depends on the roof, the vents, the windows, the clearance around the walls and what the neighbors have done with theirs. None of that is in this data. Two houses on the same street sit in the same zone whether or not one of them has been hardened.

Two packages, two responsibility areas

Responsibility for wildfire protection in California is split, and so is the mapping. The state is responsible for the State Responsibility Area, and cities and counties for the Local Responsibility Area. CAL FIRE publishes the two as separate packages, and this site loads both:

• The State Responsibility Area zones, from the FHSZSRA_23_3 package
• The Local Responsibility Area zones, from the data package dated March 24, 2025

The two differ in more than geography. Only the local data carries the Non-wildland classification; every polygon in the state data is Moderate, High or Very High. The report names which responsibility area a point falls in, because it determines who writes the rules that follow from the zone.

Where zones overlap

The zone lookup asks which zone polygons contain the point. Almost always exactly one does, and its class is the answer.

Where polygons overlap, as they can along the seam between the state and local datasets, the report gives the most hazardous class it finds rather than picking one dataset over the other. It is the conservative reading, and it means a point on a boundary will never be shown as safer than one of its sources says it is.

What the map cannot tell you

Zone edges follow modeled terrain and vegetation, not property lines. A boundary drawn through a neighborhood is not survey-accurate, and a parcel near one may be classified differently by the authority that regulates it than by a point lookup on the map.

The published zones also change, and local government has a say in them. A city or county adopts the State Fire Marshal's recommendation by ordinance, and under Government Code section 51179 it may add areas or raise a class, but it may not lower one. So the zone your jurisdiction enforces can be more severe than the state map this site draws, never less. The map shows the packages named above and nothing more recent.

Fire history

CAL FIRE Fire and Resource Assessment Program

CAL FIRE's Fire and Resource Assessment Program keeps the state's record of wildfire perimeters, compiled with the Forest Service, the Bureau of Land Management, the National Park Service and the Fish and Wildlife Service and released each spring. It reaches back to 1878, and this site loads it through the 2025 season.

How a location is matched

The report first asks which perimeters contain the point. Every fire whose perimeter does is listed, most recent first, whatever its size or age. When none does, it lists the five closest fires within 10 miles, measured to the edge of each perimeter, counting only named fires of 100 acres or more since 1950 so that each one is a fire a reader can look up.

Fire pages

Named fires since 1950 that burned 10,000 acres or more, or that damaged buildings, have a page of their own, linked from the fire lists on reports and area pages. A fire page shows the fire's dates, size and cause, the counties and communities it burned, and the earlier and later fires that burned the same land. Perimeters with the same name and start date that lie within 10 kilometers of each other are counted as one fire, such as a fire mapped in separate patches.

Building damage comes from CAL FIRE's damage inspections, which record each home, business and outbuilding inspected within 100 meters of a fire since 2013. Each inspected building is counted toward the fire it lies in or nearest to, so a lightning complex is split among its fires. Inspectors cannot always reach every building, so the counts can differ slightly from CAL FIRE's own totals.

Limits of the record

The record is incomplete, most of all for older and smaller fires: about a quarter of the perimeters have no name or start date, and nearly half have no known cause. A perimeter is the outer edge of a fire, so it can enclose patches that did not burn, and each one is simplified to about 10 meters for this site. Where an area burned more than once, the perimeters overlap, and each fire is counted.

Check the data yourself

Each agency's own map services and files

The zone classes and fire records are each agency's own, unchanged. The sections above describe everything the site does with them: the zone overlap rule and the simplified perimeters. Beyond that, zone shapes are cut into smaller pieces so a location can be looked up quickly, without moving their edges, and fire names and causes are reworded for display.

• Fire zones, state CAL FIRE FHSZSRA_23_3
• Fire zones, local CAL FIRE FHSALRA25_v1_All
• Fire history CAL FIRE California_Historic_Fire_Perimeters

Check a result with the agency

Each report links to the agency's own map service for that exact point, so you can compare its answer with the report's in one click. To check any other point, use the services in the list with your own latitude and longitude.

For example, this query asks CAL FIRE's Local Responsibility Area map which zone contains a point in Malibu. Change the numbers after geometry= (longitude first, then latitude) to check another location.

For fire history, the service can confirm which perimeters contain a point. It can't check the nearest fire when none does, and within about 10 meters of a perimeter's edge the two may differ because of the simplification.

One known difference: Simi Valley and Thousand Oaks

In part of Simi Valley and Thousand Oaks, CAL FIRE's online Local Responsibility Area map returns two classes at the same point: Very High, and the Non-wildland, High or Moderate class around it. One Very High zone in CAL FIRE's online copy has lost the holes that should surround those areas. The downloadable package dated March 24, 2025, which this site uses, has the zones as drawn, so the report shows the class from the package.