Ontario, CA Fire Regulations: Wildfire Zones (2026)
Key Facts
- CAL FIRE status
- Not in VHFHSZ
- Chapter 7A
- Not required citywide
- PRC 4291
- Defensible space rule not triggered
- Still required
- Weed abatement and Fire Code
- Map check
- CAL FIRE FHSZ viewer
Summary
Ontario sits on the valley floor and is not mapped in a CAL FIRE Very High Fire Hazard Severity Zone. Chapter 7A ignition-resistant construction and PRC 4291 defensible space do not apply citywide.
Fire Hazard Severity Zones. California's seasonally dry Mediterranean climate lends itself to wildfires, and in an effort to better prepare, CAL FIRE is required to classify the severity of fire hazard in areas of California. The History of Fire Hazard Severity Zone Maps: Fire Hazard Severity Zone maps arose from major destructive fires, prompting the recognition of these areas and strategies to reduce wildfire risks. Legislative response led to mandated mapping across California under the California Public Resources Code 4201-4204, encompassing all State Responsibility Areas (SRA). What are Fire Hazard Severity Zones? The State Fire Marshal is mandated to classify lands within State Responsibility Areas into Fire Hazard Severity Zones (FHSZ). Fire Hazard Severity Zones fall into one of the following classifications: Moderate; High; Very High. The California laws that require Fire Hazard Severity Zones include California Public Resources Code 4201-4204, California Code of Regulations Title 14, Section 1280 and California Government Code 51175-89. The Fire Hazard Severity Zone (FHSZ) maps are developed using a science-based and field-tested model that assigns a hazard score based on the factors that influence fire likelihood and fire behavior. Many factors are considered such as fire history, existing and potential fuel (natural vegetation), predicted flame length, blowing embers, terrain, and typical fire weather for the area. There are three levels of hazard in the State Responsibility Areas: moderate, high, and very high. Map Adoption Process: Classification of all lands within State Responsibility Areas into fire hazard severity zones is required by law. Therefore, the fire hazard severity zone designations and accompanying maps must follow the Administrative Procedures Act (APA) and be approved by the Office of Administrative Law (OAL). The regulation can be found in Title 14 of the California Code of Regulations (CCR) section 1280.01 and entitled "Fire Hazard Severity Zones in the SRA".
Full Breakdown
Under California Public Resources Code 4201 through 4204 and Government Code 51175 through 51189, CAL FIRE maps Fire Hazard Severity Zones for State Responsibility Areas and recommends Local Responsibility Area maps for cities. The City of Ontario, a logistics and industrial hub surrounded by the 10 and 60 freeways and Ontario International Airport, sits at the valley floor with almost no wildland-urban interface, and is therefore not included in any Very High Fire Hazard Severity Zone. This means California Building Code Chapter 7A ignition-resistant construction, the 100-foot defensible space rule under PRC 4291, and additional fire insurance disclosures tied to VHFHSZ parcels do not apply to most Ontario properties. Owners should still comply with weed abatement, safe storage of flammable liquids, and adopted Fire Code provisions. Buyers should verify zone status for any specific parcel through the CAL FIRE Fire Hazard Severity Zone viewer, particularly for properties near hillsides in adjacent cities.
Violations & Fines
Non-applicable in Ontario for VHFHSZ construction rules, but weed abatement, open burning, and fire code violations are still enforceable with administrative citations starting near 100 dollars.
Frequently Asked Questions
Is my Ontario home in a wildfire zone?
Do I need Chapter 7A ignition-resistant siding in Ontario?
Sources & Official References
Other rules in Ontario
California rules heatmap·Compare Ontario to another location·View the California fire regulations overview
See something wrong?
Help us keep this page accurate. If you notice an error or outdated information, let us know.
Wildfire Zones in Nearby Cities
How other cities in San Bernardino County handle wildfire zones.