California Wildfire Scoring Systems & Risk Maps Guide
California Insurance & Public Safety Intelligence

California Wildfire Scoring & Risk Maps

A comprehensive breakdown of state hazard mapping vs. insurance carrier risk modeling, legal policyholder rights under CCR Title 10 § 2644.9, and the mathematical factors driving your property’s fire score.

5 Major Risk Models Used in CA
0 – 30 Verisk FireLine Scale
30 Days Mandatory Appeal Window
~73% CA Homes Score 0–1

Who Creates California Wildfire Maps?

California relies on 5 primary risk systems divided between public safety agencies and commercial insurance underwriters.

Government / Public

CAL FIRE (FHSZ)

Fire Hazard Severity Zones

Managed by the Office of the State Fire Marshal. Evaluates 30-to-50-year regional fire hazard horizons based on topography, vegetation (fuel), weather, and ember projection.

Rating Scale: Moderate / High / Very High
Primary Purpose: Building Codes & Disclosures
Impacts: Chapter 7A WUI, 100-ft Space
Admitted & FAIR Plan

Verisk Analytics / ISO

FireLine® Risk Score

The primary wildfire score used by CA admitted homeowners insurance carriers and the California FAIR Plan. Focuses on individual property terrain, access, and surrounding fuel density.

Rating Scale: 0 to 30 Scale
Primary Purpose: Insurance Underwriting / Rates
Key Formula: Fuel × Slope × Access
Proprietary Carrier

CoreLogic

Wildfire Risk Score

Evaluates micro-level environmental exposure. Analyzes slope orientation (aspect), localized wind patterns, historical fire perimeters, and physical distance to WUI boundaries.

Rating Scale: 1 to 100 Scale
Primary Purpose: Risk Modeling & Portfolio Analysis
Tiers: Low, Moderate, High, Extreme
AI & Satellite

ZestyAI

Z-FIRE™ Machine Learning Model

Utilizes high-resolution aerial imagery and machine learning to analyze structure-specific parameters including roof composition, tree overhang, deck material, and localized defensible space.

Rating Scale: Property Risk Band Index
Primary Purpose: Granular Home Hardening Credit
Inputs: 200+ Image Data Points
Municipal Safety

ISO Public Protection

PPC Rating System

Measures the capacity of the local municipal fire department, water supply pressure, fire hydrants, and station proximity. It rates community fire defense capability rather than brush risk.

Rating Scale: 1 to 10 (1 is Best)
Primary Purpose: Basic Municipal Fire Rating
Focus: Water Pressure & Station Distance

State Hazard vs. Carrier Score

A property can be located in a CAL FIRE "Very High FHSZ" due to regional climate, yet maintain a low Verisk FireLine score if surrounding terrain and fuel clearance immediately around the lot are favorable.

Verisk FireLine® Deep Dive

Understanding the 0 to 30 Scoring Scale

How Verisk Analytics evaluates terrain factors and calculates statewide California distribution.

Ember Drift Warning: A FireLine score of 0 does not indicate zero risk. Windborne embers can travel over 1 to 2 miles ahead of an active wildfire front.
California Statewide Address Distribution Breakdown Source: ISO/Verisk Property Analytics
0-1 (73%)
2-3 (12%)
4-6 (5%)
7-12 (4%)
13-15 (2%)
16-30 (4%)

* Bar visual proportions adjusted to ensure label clarity across all ranges.

Scores 0 – 1 ~73% of CA
Negligible to Low Risk

Detailed Breakdown:
• Score 0: Minimal or no fuel within 100–2,500ft. Flat/gentle slope.
• Score 1: Very low brush density, flat ground, clear access. Standard eligibility across virtually all carriers.

Scores 2 – 3 ~12% of CA
Low to Moderate Risk

Detailed Breakdown:
• Score 2: Light fuel proximity or minor slope (10–20%).
• Score 3: Moderate light fuel with mild incline or limited access. Most admitted carriers still write, sometimes with minor rating surcharges.

Scores 4 – 6 ~5% of CA
Moderate to High Risk

Detailed Breakdown:
• Score 4: Moderate fuel density + moderate slope (20–30%).
• Score 6: Heavy fuel proximity or steep slope with standard road access. Triggers strict underwriting guidelines and mandatory home hardening reviews.

Scores 7 – 12 ~4% of CA
High Risk

Detailed Breakdown:
• Heavy fuel concentration, steep canyon inclines, and restricted access road networks requiring specialized underwriting approvals or premium adjustments.

Scores 13 – 15 ~2% of CA
Very High Risk

Detailed Breakdown:
• Severe topographic exposure, continuous heavy brush canopy, and limited emergency turnaround access. Frequently subject to carrier restrictions.

Scores 16 – 30 ~4% of CA
Extreme Risk

Detailed Breakdown:
• Maximum hazard exposure combining extreme fuel loads, hazardous slope orientations, and dead-end egress. Primary driver of California FAIR Plan assignments.

Core Scoring Formula Visualizer

FireLine Risk ≈ Fuel × Slope × Access (+ SHIA Overlay)

Medium Density

Evaluates volume, brush type, and continuous tree canopy within 2,500ft radius.

Moderate Incline

Fires accelerate rapidly uphill by preheating brush above structure.

Standard Access

Evaluates dead-ends, narrow one-lane roads, and emergency truck turnarounds.

4 Moderate Risk

Estimated FireLine® Score

Property will likely require standard underwriting review or surcharge in CA.

CCR Title 10 § 2644.9 & "Safer from Wildfires"

California Policyholder Legal Protection & Appeal Rights

Enforced by the California Department of Insurance (CDI). Insurance companies must provide score transparency and offer mandatory discounts for mitigation.

1

Right to Your Score

Insurers must disclose the exact wildfire risk score assigned to your property whenever a policy is written, renewed, or non-renewed, alongside detailed explanations of the rating factors.

2

30-Day Appeal Window

Policyholders have the legal right to contest an inaccurate wildfire score. Insurers must respond to formal appeals within 30 days and re-evaluate property modifications or errors.

3

Mandatory Discounts

Under "Safer from Wildfires" regulations, admitted carriers must offer rate discounts for home hardening (e.g., Class A roof, ember-resistant vents) and defensible space measures.