Sierra County Disaster Risk
Sierra County, California
FEMA Risk Rating
Very Low
National Percentile
32th
of 3,144 counties
State Rank
#57
of 58 (1 = highest risk)
Flood Risk
38th
percentile
Hazard Risk Breakdown
Flood
River, coastal, and surface flooding risk
Very Low
Higher than 38% of US counties
Wildfire
Wildland and wildland-urban interface fire risk
Relatively High
Higher than 96% of US counties
Tornado
Tornado and severe thunderstorm risk
Very Low
Higher than 2% of US counties
Earthquake
Seismic activity and ground shaking risk
Relatively Low
Higher than 67% of US counties
Risk Overview
About Natural Disaster Risk in Sierra County, California
Sierra County faces below-average risk
Sierra County's composite risk score of 31.52 earns a 'Very Low' rating and falls significantly below the national average. This rural, mountainous county's overall vulnerability is notably lower than most of California, though specific hazards still require attention.
California's safest county overall
Sierra's 31.52 score is far below California's 88.72 average, making it the state's lowest-risk county by a substantial margin. The county's low population density and distance from major fault lines contribute to its exceptional safety profile.
Significantly safer than surrounding counties
Sierra (31.52) faces dramatically lower risk than neighboring Shasta (93.38) and Siskiyou (89.03), making it a notable exception in northern California's hazard profile. The county's high elevation and remote location insulate it from many regional risks.
Wildfire remains the primary concern
Sierra's wildfire risk scores 95.58, reflecting the county's extensive forest cover and elevation, despite overall low composite risk. Flood risk (37.69) and earthquake risk (66.83) are moderate by state standards, posing less immediate threat than fire.
Wildfire insurance protects mountain homes
Sierra County residents should focus on wildfire insurance given the 95.58 risk score, even as other hazards remain relatively low. Defensible space maintenance and community fire preparedness are equally important protections for this forest-dependent county.
Source: FEMA National Risk Index · Narrative reviewed by Evan Brooks, Data Editor
Preparedness Guide
What to Prepare for in Sierra County
Top Hazards by Exposure
Source: FEMA National Risk Index v1.19.0 · Percentiles are national (3,144 counties)
Risk Advisory: Sierra County
Risk Verdict
Sierra County sits in the lower tier of U.S. counties for natural disaster exposure, ranked at the 32th percentile nationally. The 32th percentile national ranking is one lens; Sierra County residents also benefit from reviewing which specific hazard types drive the county's composite score and preparing accordingly.
Hazard Breakdown
Wildfire risk is Sierra County's dominant natural hazard, ranked at the 96th percentile nationally under FEMA's National Risk Index. Earthquake ranks second at the 67th percentile nationally. Additional tracked hazards include flood (38th percentile), tornado (2th percentile).
Preparedness Context
At the 96th percentile nationally for wildfire risk, Sierra County households benefit from creating defensible space — a buffer of reduced vegetation around structures — and reviewing whether homeowners insurance covers wildfire damage in this region. The county's earthquake exposure at the 67th percentile nationally complements the wildfire risk — saturating rain after burn scarring often triggers secondary flood and debris flow events. Enrolling in the county's wireless emergency alert system and keeping a vehicle at least half-full during peak fire season are low-cost habits that dramatically reduce evacuation lag time for Sierra County residents.
Regional Context
Sierra County falls 57.2 points below California's typical county risk level, making it one of the safer natural-hazard environments in the state.
Is your household prepared for Sierra County's hazards?
Review FEMA's county-specific preparedness checklists and emergency planning guides.
Frequently Asked Questions
What is the natural disaster risk in Sierra County, CA?
What types of natural hazards affect Sierra County?
How does Sierra County risk compare to the California average?
Is Sierra County at risk for wildfire?
How is natural disaster risk measured?
Is Sierra County a safe place to live?
Data Source
Risk data sourced from the FEMA National Risk Index (NRI). Risk scores are relative rankings (0–100) across all US counties — not absolute risk measures. Higher scores indicate higher relative risk compared to other counties.
Disclaimer: This data is informational only. It is not financial, insurance, or legal advice. Always consult a qualified professional before making insurance or real estate decisions.