Fire Hazard Severity Zones:
How They Impact Your Home Insurance

What Are Fire Hazard Severity Zones (FHSZs)

FHSZs are geographic designations developed by CAL FIRE to reflect a property’s likelihood of experiencing wildfire. Only areas with wildfire risk are categorized as a FHSZ Moderate, High, or Very High. These are based on a combination of environmental and historical data, including:

• Vegetation and fuel density
• Topography (e.g., slope and elevation)
• Prevailing wind and ember flow patterns
• Local fire history and climate trends
• Proximity to wildland areas and ignition points

According to CAL FIRE’s 2024 update, FHSZs play a critical role in determining building codes, permit approvals, and fire safety regulations. While the maps themselves are not binding on insurance providers, they can indirectly influence home insurance availability and pricing, particularly when paired with private wildfire risk models such as HazardHub.

If your property falls in a High or Very High zone, it’s more likely to be subject to fire inspections and regulations because structures in that area are at greater risk for wildfire damage. That designation affects more than just your peace of mind; it can influence building codes, permit approvals, and even your ability to manage landscape to suit your personal preference.

Why California Is Updating the Maps

The threat of wildfire in California is no longer seasonal or localized. With climate change, extreme droughts, and urban expansion into fire-prone terrain, risks are rising. As the number of wildfires increases along with the number of homes in harm’s way, it becomes more apparent that fire fighting resources can no longer focus on structure defense or emergency rescues if they are to make quick progress in controlling the spread of the fire. Going forward, communities and structures need to be more resilient to wildfire. New WUI Codes ensure this resiliency in High or Very High FHSZs which makes the designation a critical step in community-level retro-fitting and widespread code adoption.

In the 2023 fire season, over 8,000 wildfires burned more than 1 million acres and destroyed 2,400 structures across California, according to CAL FIRE’s incident reports. To address growing risk, CAL FIRE released its updated Fire Hazard Severity Zone maps in 2024. Many communities once considered low-risk are now reclassified.

For homeowners newly classified into High or Very High Zones, this shift can bring surprise, stress, and financial strain. Understanding why these changes occurred helps residents prepare and adapt rather than panic.

How Your Zone Affects Home Insurance

Being in a High or Very High zone can make it harder—and more expensive—to protect your home. When risk levels are too high and wildfire damage is inevitable, carriers may refuse to insure your home or increase your premium to match expected future loss. However, being in a FHSZ can qualify property owners for grant assistance to make critical improvements to the risk profile and potentially qualify for insurance discounts. Without mitigation, some properties in the FHSZ will not be insurable.

According to the California Department of Insurance Fact Sheet on residential insurance policy counts, the statewide nonrenewal rate for homeowners and dwelling fire policies rose from approximately 11 percent in 2018 to about 13 percent in 2021.

Tammy Schwartz, Senior Director of Analytics at Guidewire emphasized that increases in nonrenewals may simply reflect broader market dynamics—like expansion in policy volumes or stock—rather than insurers pulling back from high-risk areas. Homeowners should not assume zone reclassifications automatically result in coverage loss. Instead, they should assess personal wildfire risk and consider mitigation upgrades to protect their policy status.

To be sure your home still qualifies for coverage at the end of the policy term, insurers may require additional wildfire mitigation over time, such as defensible space clearance or roof upgrades. If your only option is the California FAIR Plan, you’ll also need a DIC (Differences in Conditions) policy to cover liability, theft, and water damage–none of which are included in the FAIR plan’s fire-only coverage.

“Insurers rely on precise, property-level data to underwrite wildfire risk,” says Schwartz. “Carriers will consider many things in assessing your risk. Knowing your zone informs you when mitigation steps will matter most and risk reduction efforts can go a long way towards reducing any coverage gaps.”

Key Mitigation Steps for High-Risk Zones

Homeowners in High and Very High zones often ask: where do I begin? The question we should be asking is where does it end? Starting isn’t enough. Mitigation against wildfire must be comprehensive. It isn’t enough to do or two things. Imagine you’re repairing a boat with holes along the bottom of the hull. Filling a few of them doesn't reduce the risk of sinking. To really change the risk profile, you must fill all of the holes. That said, most of us don’t have unlimited time or money so people often start with the things that can be done most easily with the biggest impact. If you’re in that boat, start here:

• Clear the first 0–5 feet around your home of flammable debris and vegetation
• Install ember-resistant vents in all openings (attic vents, eave vents, crawl space vents, flood vents, etc.) with 1/8-inch mesh screens
• Enclose your eaves and fire proof your decks
• Use fire-resistant native plants in landscaping away from windows and remove wood mulch or replace with gravel or stone

These actions align with NFPA 1140 and CAL FIRE defensible space guidelines and may be required by local code depending on your property’s zone.

How Insurers Evaluate Wildfire Risk Today

Insurers have moved beyond generalizations like ZIP codes or county-level fire history. Today, wildfire risk is assessed at a specific location using:

• HazardHub wildfire scores, which analyze parcel-level exposure based on topography, climate, fuel load, and suppression capacity
• IBHS Fortified Home assessments, which document structural resilience and retrofits
• Satellite and LIDAR imagery: High-resolution tools that model ember reach, flame path, and fuel presence in real time. LIDAR (Light Detection and Ranging) uses laser scanning to capture precise elevation and surface data, helping model how fire spreads across terrain.

This type of granular scoring allows insurers to adjust premiums based on real, observable risk and enables proactive homeowners to qualify for better coverage.

“Property-specific scoring replaces guesswork,” says Schwartz. “It lets insurers focus on only those properties with risk where it makes sense to reward risk reduction and helps homeowners focus their efforts where they matter most.”

Policy Gaps You Shouldn’t Overlook

Many assume that having a policy means full protection. It doesn’t. Sometimes, people with homes that survive are harmed the most. They don’t have an insurance recovery and they still have their lives upended and community destroyed, even if only temporarily.

Standard homeowners’ insurance doesn’t cover:

• cleaning services
• locating replacement services for in-home medical care
• finding child care or local jobs during the recovery period
• recovery from PTSD that results from surviving a tragedy such as this

In a 2023 DOI consumer bulletin, officials warned that even well-insured homes could face thousands in uninsured recovery costs after a fire.

Resilience Starts at Home: Your Fire Safety Checklist

Wildfire protection doesn’t stop at your property line. It also includes how well you and your household are prepared to act if a fire breaks out. Nobody wants their kitchen to be the source of a wildfire that destroys thousands of homes. Here’s a simple checklist every homeowner should follow:

• Smoke alarms on every level and in every sleeping area 
• Fire extinguishers in the kitchen, garage, and near exits
• Two exit routes from each room
• A family evacuation plan with a map and designated meeting place
• Emergency contact list shared and accessible
• Regular monthly checks of alarms and extinguishers

Why Community Resilience Matters

Your property’s fire preparedness is only part of the insurance picture. Carriers are increasingly evaluating community-level resilience, which includes:

• Accessible roads and turnarounds
• firewise and wildfire prepared communities
• Local fire suppression infrastructure
• historical wildfire suppression success rates

For example, Mercury has agreed to reenter the California market and offer coverage to homeowners in Paradise, CA, where residents have taken on the arduous task of rebuilding the Paradise community to the IBHS Wildfire Prepared Community standards. Only one other community in the nation will be able to achieve this status in 2025, and that is a brand new community being built near San Diego, CA. Properties in this community can now purchase a preferred insurance policy from Mercury Insurance, CA - domiciled, for $2000 compared to coverage through the FAIR plan for approximately $8000.

Organizations like the NAIC and IBHS provide tools and checklists for assessing community wildfire resilience. These can help neighborhoods improve their collective recovery capacity and insurance profiles.

How to Take Action Today

Not sure what your risk score looks like? Don’t wait for your policy to be dropped or your premium to spike. Take the Guidewire HazardHub quiz to get personalized insights on your home’s wildfire exposure and what you can do to lower it. A few smart changes now could make a major difference later.