San Juan County Disaster Risk
San Juan County, Washington
FEMA Risk Rating
Very Low
National Percentile
35th
of 3,144 counties
State Rank
#33
of 39 (1 = highest risk)
Flood Risk
58th
percentile
Hazard Risk Breakdown
Flood
River, coastal, and surface flooding risk
Relatively Low
Higher than 58% of US counties
Wildfire
Wildland and wildland-urban interface fire risk
Very Low
Higher than 41% of US counties
Tornado
Tornado and severe thunderstorm risk
Very Low
Higher than 4% of US counties
Earthquake
Seismic activity and ground shaking risk
Moderate
Higher than 89% of US counties
Risk Overview
About Natural Disaster Risk in San Juan County, Washington
San Juan County has very low disaster risk
San Juan County scores 35.37 on the composite risk scale, well below Washington's state average of 70.01 and in the very low risk category nationally. This island county faces less frequent or severe natural hazard exposure than the typical American county. Its marine location and relatively protected geography create a favorable disaster risk profile compared to mainland Washington communities.
Among Washington's safest counties
San Juan County ranks in the bottom tier for disaster risk statewide, with a 35.37 score comparable to Pend Oreille County (28.02) and Skamania County (49.68). The county's low scores reflect minimal tornado (4.42) and wildfire (41.32) risks, though earthquake risk is higher at 89.44 due to regional tectonics. San Juan is one of only three Washington counties scoring below 40 on the composite scale.
Island safety with seismic considerations
San Juan County's 35.37 score is lower than neighboring Skagit County (88.77) on the mainland and comparable to remote Pend Oreille County (28.02). San Juan's earthquake risk (89.44) is high relative to its overall score, reflecting the same Cascadia Subduction Zone exposure as western Washington counties despite lower composite risk. Wildfire and tornado risks in San Juan are dramatically lower than mainland neighbors due to marine climate and isolation.
Earthquakes and flooding top the list
Earthquake risk (89.44) is San Juan County's most significant threat, with the Cascadia Subduction Zone affecting the islands despite their protected island location. Flood risk (58.40) is moderate and primarily affects low-lying areas and marine infrastructure during storm surge events. Tornado (4.42) and wildfire (41.32) risks are minimal for island communities, making seismic preparedness the clear priority.
Earthquake insurance and storm preparedness
San Juan County homeowners should prioritize earthquake insurance coverage, as standard homeowners policies exclude seismic damage. Ensure your property is built or retrofitted to modern seismic standards, particularly if you own older structures or waterfront property vulnerable to tsunami hazards. While wildfire risk is low, review emergency evacuation plans for island communities, where ferry access may be limited during major events.
Source: FEMA National Risk Index · Narrative reviewed by Evan Brooks, Data Editor
Preparedness Guide
What to Prepare for in San Juan County
Top Hazards by Exposure
Source: FEMA National Risk Index v1.19.0 · Percentiles are national (3,144 counties)
Risk Advisory: San Juan County
Risk Verdict
At the 35th percentile nationally, San Juan County experiences relatively limited natural hazard pressure compared to most of the country. A preparedness foundation — alert registration, household communication plan, and a basic supply review — costs little and remains valuable even at San Juan County's favorable 35th percentile ranking.
Hazard Breakdown
Earthquake risk is San Juan County's dominant natural hazard, ranked at the 89th percentile nationally under FEMA's National Risk Index. Flood ranks second at the 58th percentile nationally. Additional tracked hazards include wildfire (41th percentile), tornado (4th percentile).
Preparedness Context
San Juan County ranks at the 89th 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. Alongside earthquake exposure, San Juan County's flood risk at the 58th percentile nationally reinforces the value of maintaining a household emergency supply cache usable for multiple hazard scenarios. For earthquake preparedness, San Juan 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
A composite score 34.6 points below the Washington state average puts San Juan County in a better-than-typical position relative to neighboring counties.
Is your household prepared for San Juan County's hazards?
Review FEMA's county-specific preparedness checklists and emergency planning guides.
Frequently Asked Questions
What is the natural disaster risk in San Juan County, WA?
What types of natural hazards affect San Juan County?
How does San Juan County risk compare to the Washington average?
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How is natural disaster risk measured?
Is San Juan 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.