Snohomish County
Washington — Natural Disaster Risk Assessment
HighComposite Risk Score
National percentile: 98th
Snohomish County faces high composite natural disaster risk (NRI Risk Index score 97.9, 98th national percentile), driven primarily by landslide and earthquake exposure. Expected annual loss across all 18 hazard types is $409M.
Source: FEMA National Risk Index v1.20 · Updated December 2025
Top Hazards
All 18 Hazard Risks
| Landslide | Very High | 4.12 / yr | $25M |
| Earthquake | High | 0.04 / yr | $247M |
| Ice Storm | Very High | 0.45 / yr | $4M |
| Heat Wave | High | 3.36 / yr | $12M |
| Volcanic Activity | Medium | 0.01 / yr | $675K |
| Riverine Flood | High | 0.39 / yr | $112M |
| Winter Weather | High | 31.89 / yr | $761K |
| Avalanche | High | 0.30 / yr | $2M |
| Lightning | High | 8.63 / yr | $1M |
| Coastal Flood | Medium | 3.18 / yr | $2M |
| Cold Wave | Low | 0.04 / yr | $2M |
| Wildfire | Very Low | 0.00 / yr | $120K |
| Tornado | Low | 0.05 / yr | $1M |
| Hail | Very Low | 0.03 / yr | $66K |
| Drought | Very Low | 4.72 / yr | $44 |
| Strong Wind | Very Low | 0.02 / yr | $74K |
| Tsunami | Very Low | 0.06 / yr | $51K |
| Hurricane | Very Low | 0.00 / yr | $0 |
Frequently Asked Questions
What is the overall natural disaster risk for Snohomish County?
Snohomish County has a composite FEMA National Risk Index score of 97.9 out of 100, placing it in the High category and the 98th national percentile. This combines Expected Annual Loss, Social Vulnerability, and Community Resilience across 18 hazard types.
What are the top natural hazards in Snohomish County?
The three highest-rated hazards are Landslide (Very High, $25M EAL), Earthquake (High, $247M EAL), Ice Storm (Very High, $4M EAL). These account for most of the county's expected annual losses.
How does Snohomish County compare to other Washington counties?
Snohomish County ranks #3 of 39 Washington counties for overall natural disaster risk, with a high 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. Snohomish County's $409M EAL is a statistical average, not a guarantee for any specific year or address.