San Juan County

Washington — Natural Disaster Risk Assessment

Very Low

Composite Risk Score

35.4

National percentile: 35th

San Juan County faces very low composite natural disaster risk (NRI Risk Index score 35.4, 35th national percentile), driven primarily by earthquake and landslide exposure. Expected annual loss across all 18 hazard types is $10M.

Source: FEMA National Risk Index v1.20 · Updated December 2025

Expected Annual Loss $10M Annualized county-level EAL
Social Vulnerability High Population sensitivity
Community Resilience Very High Capacity to recover
Population 18K Latest estimate

Top Hazards

Earthquake
Low $4M/yr
Landslide
Very Low $3K/yr
Winter Weather
Low $79K/yr

All 18 Hazard Risks

Earthquake Low 0.02 / yr $4M
Landslide Very Low 0.33 / yr $3K
Winter Weather Low 4.79 / yr $79K
Coastal Flood Low 3.63 / yr $354K
Riverine Flood Low 0.04 / yr $5M
Wildfire Very Low 0.00 / yr $25K
Volcanic Activity Very Low 0.00 / yr $4
Cold Wave Low 0.52 / yr $398K
Ice Storm Very Low 0.04 / yr $13K
Heat Wave Very Low 0.47 / yr $28K
Tsunami Very Low 0.06 / yr $31K
Lightning Very Low 4.28 / yr $15K
Tornado Very Low 0.01 / yr $13K
Hail Very Low 0.01 / yr $808
Strong Wind Very Low 0.00 / yr $1K
Avalanche Very Low 0.00 / yr $0
Drought Very Low 0.00 / yr $0
Hurricane Very Low 0.00 / yr $0

Frequently Asked Questions

What is the overall natural disaster risk for San Juan County?

San Juan County has a composite FEMA National Risk Index score of 35.4 out of 100, placing it in the Very Low category and the 35th national percentile. This combines Expected Annual Loss, Social Vulnerability, and Community Resilience across 18 hazard types.

What are the top natural hazards in San Juan County?

The three highest-rated hazards are Earthquake (Low, $4M EAL), Landslide (Very Low, $3K EAL), Winter Weather (Low, $79K EAL). These account for most of the county's expected annual losses.

How does San Juan County compare to other Washington counties?

San Juan County ranks #33 of 39 Washington counties for overall natural disaster risk, with a very low rating.

What does Expected Annual Loss (EAL) mean?

EAL is FEMA's estimate of average annual dollar losses from natural hazards, calculated from historical event data and exposure models. San Juan County's $10M EAL is a statistical average, not a guarantee for any specific year or address.