Santa Clara County, CA Fire Regulations: Wildfire Zones (2026)

Unincorporated Santa Clara County contains extensive wildland-urban interface (WUI) and high-wildfire-risk terrain, including the Santa Cruz Mountains to the west and the Diablo Range foothills to the east. CAL FIRE classifies land into Moderate, High, and Very High Fire Hazard Severity Zones; on February 24, 2025, CAL FIRE released updated Local Responsibility Area (LRA) Fire Hazard Severity Zone maps, and the County maintains its own interactive maps. The Santa Clara County Fire Marshal has, for simplicity, grouped the new mapping into the main body of the Wildland-Urban Interface and the 'Very High Fire Hazard Severity Zone' within it. Zone designation is based on fuel loading, slope, fire weather, and wind-driven spread factors identified by the Office of the State Fire Marshal. Being mapped in a High or Very High zone, or within the WUI, carries real obligations: 100 feet of defensible space under PRC 4291, ignition-resistant construction under the California WUI building standards (Chapter 7A) for new and substantially remodeled homes, and inspection by the county fire marshal. Most unincorporated land is also a State Responsibility Area where CAL FIRE shares wildfire protection responsibility. Property owners can confirm their parcel's classification using the County's Fire Hazard Severity Zone viewer or CAL FIRE's statewide maps; the designation also affects development review, vegetation-management requirements, and wildfire insurance availability.