Lewis County Disaster Risk
Lewis County, Washington
FEMA Risk Rating
Relatively Moderate
National Percentile
90th
of 3,144 counties
State Rank
#15
of 39 (1 = highest risk)
Flood Risk
91th
percentile
Hazard Risk Breakdown
Flood
River, coastal, and surface flooding risk
Moderate
Higher than 91% of US counties
Wildfire
Wildland and wildland-urban interface fire risk
Relatively Low
Higher than 77% of US counties
Tornado
Tornado and severe thunderstorm risk
Very Low
Higher than 17% of US counties
Earthquake
Seismic activity and ground shaking risk
Relatively High
Higher than 97% of US counties
Risk Overview
About Natural Disaster Risk in Lewis County, Washington
Lewis County faces relatively moderate risk
Lewis County's composite risk score of 89.69 ranks in the "Relatively Moderate" category, above the national average. The score reflects significant exposure to flooding, earthquakes, and wildfires concentrated in specific geographic zones.
Above average risk across Washington
Lewis County scores 89.69 against Washington's state average of 70.01, placing it among the state's higher-hazard regions. The elevated score is driven primarily by extreme flood vulnerability and substantial earthquake exposure.
Lewis County sits in high-risk band
Lewis County (89.69) exceeds nearby Mason County (85.34) and Kittitas County (89.12), ranking it among south-central Washington's most hazard-exposed counties. The difference reflects Lewis's pronounced flood risk from the Cowlitz and Lewis Rivers.
Flooding and earthquakes lead threats
Lewis County faces extreme flood risk (90.90), affecting communities along the Cowlitz and Lewis Rivers with seasonal and storm surge dangers. Earthquakes (97.33) pose a secondary but severe threat across the entire county, while wildfires (76.69) affect forested areas.
Flood and earthquake coverage essential
Lewis County residents should obtain flood insurance immediately, especially those near rivers or in low-lying areas—standard homeowners policies exclude flood damage. Pair this with earthquake insurance to cover seismic damage, and ensure your home's foundation is secured against ground shaking.
Source: FEMA National Risk Index · Narrative reviewed by Evan Brooks, Data Editor
Preparedness Guide
What to Prepare for in Lewis County
Top Hazards by Exposure
Source: FEMA National Risk Index v1.19.0 · Percentiles are national (3,144 counties)
Risk Advisory: Lewis County
Risk Verdict
Lewis County's overall risk score at the 90th percentile nationally signals meaningful exposure to multiple natural hazard types. Comprehensive household preparedness — including reviewing insurance, maintaining emergency supplies, and knowing evacuation routes — is strongly recommended.
Hazard Breakdown
Earthquake risk is Lewis County's dominant natural hazard, ranked at the 97th percentile nationally under FEMA's National Risk Index. Flood ranks second at the 91th percentile nationally. Additional tracked hazards include wildfire (77th percentile), tornado (17th percentile).
Preparedness Context
Lewis County ranks at the 97th percentile nationally for earthquake risk. Unlike most natural hazards, earthquakes provide no advance warning; preparedness here means structural adjustments and a practiced response, not alert monitoring. The county's flood risk at the 91th percentile nationally is a seasonal consideration alongside the year-round earthquake threat, requiring awareness of both hazard types. For earthquake preparedness, Lewis County's county emergency management office often maintains a list of community water supply points, Red Cross shelter locations, and post-quake assistance programs — useful resources to identify before an event occurs.
Regional Context
Compared to other Washington counties, Lewis County runs 19.7 composite risk points higher than the state mean — reflecting above-average hazard concentration in this area.
Is your household prepared for Lewis County's hazards?
Review FEMA's county-specific preparedness checklists and emergency planning guides.
Frequently Asked Questions
What is the natural disaster risk in Lewis County, WA?
What types of natural hazards affect Lewis County?
How does Lewis County risk compare to the Washington average?
Is Lewis County at risk for earthquake?
How is natural disaster risk measured?
Why is Lewis County higher risk than average?
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.