Guidewire HazardHub: 1M California Homes at High Wildfire Risk as Mitigation Cuts Losses by 70%

New wildfire analysis from Guidewire HazardHub classifies over one million California homes as "very high risk," while showing that property-level mitigation can cut expected losses by up to 70%. The comprehensive dataset reveals evolving exposure across suburban and wildland-urban interface (WUI) zones nationwide, giving insurers parcel-level visibility to better price and manage catastrophe risk.

Built on HazardHub parcel-level data, historical wildfire modeling, and inspection research, the study provides a detailed roadmap of evolving catastrophe exposure across the United States.

While California continues to lead the nation in total high-risk properties, with more than one million homes receiving HazardHub's highest "F" wildfire risk designation ("very high risk"), the study revealed additional key findings, including:

• Top 10 states by total homes at "very high risk" (F-rated): California, Arizona, Colorado, Oregon, New Mexico, Washington, Nevada, Montana, Texas, and Idaho.
• Texas enters the top 10 with 31,106 "F-rated" homes, highlighting growing wildfire exposure outside traditionally recognized Western markets.
• Top 5 states by percentage of homes at "very high risk": Montana, California, New Mexico, Wyoming, and Oregon.

The findings indicate that wildfire exposure is expanding alongside population growth, suburban development, and the growth of the wildland-urban interface (WUI). However, analysis shows that exposure in California remains highly concentrated as approximately 98% of wildfire-related property damage occurs within roughly 10% of the state's highest-risk properties.

"Wildfire exposure, particularly in California, is highly concentrated and variable at the property level," said Chris Folkman, Vice President, HazardHub at Guidewire. "Broad regional assumptions overlook meaningful differences between neighboring properties. Parcel-level intelligence helps insurers recognize individual mitigation efforts, price risk accurately, and support broader insurance availability."

Recent research conducted jointly by the Insurance Information Institute (Triple-I) and Guidewire HazardHub found that neighboring properties within the same wildfire-prone ZIP code can differ by more than fourfold in overall risk scores. Factors such as vegetation density, topography, defensible space, and fire suppression access create vastly different risk profiles on the same street.

Analyzing approximately 91,800 California home inspections alongside historical damage data, HazardHub identified massive loss-reduction benefits tied to property hardening:

• Defensible Space: Homes with well-maintained defensible space were 65% less likely to experience significant wildfire damage.
• Ember-Resistant Vents: Properties with ember-resistant vents showed a 40% lower likelihood of ignition compared to unmitigated homes.
• Comprehensive Mitigation: Combining multiple resiliency measures reduced overall expected wildfire losses by up to 70%.

These findings support the California Sustainable Insurance Strategy's goal of expanding insurance availability through advanced risk modeling and mitigation incentives.