Mason County Disaster Risk
Mason County, Washington
FEMA Risk Rating
Relatively Moderate
National Percentile
85th
of 3,144 counties
State Rank
#20
of 39 (1 = highest risk)
Flood Risk
79th
percentile
Hazard Risk Breakdown
Flood
River, coastal, and surface flooding risk
Relatively Low
Higher than 79% of US counties
Wildfire
Wildland and wildland-urban interface fire risk
Relatively Low
Higher than 44% of US counties
Tornado
Tornado and severe thunderstorm risk
Very Low
Higher than 14% 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 Mason County, Washington
Mason County faces relatively moderate risk
Mason County's composite risk score of 85.34 ranks in the "Relatively Moderate" category, above the national average. The score reflects significant earthquake exposure paired with notable flood and wildfire threats.
Above average risk for Washington state
Mason County scores 85.34 against Washington's state average of 70.01, placing it in the upper half of state county risk rankings. This elevated score is primarily driven by severe earthquake hazard affecting the entire county.
Mason sits below King, above inland peers
Mason County (85.34) falls significantly below nearby King County (99.68) and Kitsap County (92.30) but exceeds distant Klickitat County (73.89). Its position reflects Hood Canal and Puget Sound proximity with associated seismic risks.
Earthquakes and flooding threaten Mason
Mason County faces severe earthquake risk (97.20) from the Cascadia Subduction Zone and local faults, plus notable flood exposure (79.29) along Puget Sound and river valleys. Wildfire risk (44.05) is moderate, concentrated in eastern forested areas.
Earthquake and flood insurance vital
Mason County residents should secure both earthquake and flood insurance, as standard policies exclude both hazards. Waterfront and riverside properties face particular risk; ensure your coverage reflects potential earthquake damage to older structures and flood loss in low-lying neighborhoods.
Source: FEMA National Risk Index · Narrative reviewed by Evan Brooks, Data Editor
Preparedness Guide
What to Prepare for in Mason County
Top Hazards by Exposure
Source: FEMA National Risk Index v1.19.0 · Percentiles are national (3,144 counties)
Risk Advisory: Mason County
Risk Verdict
Natural hazard risk in Mason County is higher than the majority of U.S. counties, with a national composite rank of 85th. Mason County's elevated composite score reflects cumulative multi-hazard exposure; households should prepare for the county's two or three primary hazard types.
Hazard Breakdown
Earthquake risk is Mason County's dominant natural hazard, ranked at the 97th percentile nationally under FEMA's National Risk Index. Flood ranks second at the 79th percentile nationally. Additional tracked hazards include wildfire (44th percentile), tornado (14th percentile).
Preparedness Context
At the 97th percentile nationally for earthquake risk, Mason County is in a zone where a post-earthquake communications plan matters almost as much as pre-earthquake structural preparation — phone networks are typically congested for hours after a significant event. Flood at the 79th percentile nationally is a separate hazard dimension for Mason County that requires different protective strategies from earthquake preparedness. For Mason County households, the three highest-impact earthquake preparedness actions are: (1) anchor heavy furniture and water heaters, (2) store three days of water at one gallon per person per day, and (3) identify a family reunification plan for the post-quake communication blackout period.
Regional Context
A composite score 15.3 points above the Washington state average puts Mason County in a higher-risk category than most counties in the state.
Is your household prepared for Mason County's hazards?
Review FEMA's county-specific preparedness checklists and emergency planning guides.
Frequently Asked Questions
What is the natural disaster risk in Mason County, WA?
What types of natural hazards affect Mason County?
How does Mason County risk compare to the Washington average?
Is Mason County at risk for earthquake?
How is natural disaster risk measured?
Why is Mason 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.