Lewis County
Washington — Natural Disaster Risk Assessment
MediumComposite Risk Score
National percentile: 90th
Lewis County faces medium composite natural disaster risk (NRI Risk Index score 89.7, 90th national percentile), driven primarily by earthquake and landslide exposure. Expected annual loss across all 18 hazard types is $71M.
Source: FEMA National Risk Index v1.20 · Updated December 2025
Top Hazards
All 18 Hazard Risks
| Earthquake | Medium | 0.02 / yr | $30M |
| Landslide | Medium | 5.75 / yr | $195K |
| Volcanic Activity | Medium | 0.01 / yr | $287K |
| Riverine Flood | Medium | 0.29 / yr | $37M |
| Avalanche | High | 0.70 / yr | $1M |
| Heat Wave | Low | 3.24 / yr | $1M |
| Wildfire | Low | 0.00 / yr | $263K |
| Winter Weather | Low | 29.26 / yr | $40K |
| Ice Storm | Low | 0.51 / yr | $37K |
| Lightning | Low | 6.58 / yr | $103K |
| Strong Wind | Low | 0.02 / yr | $168K |
| Tornado | Very Low | 0.14 / yr | $162K |
| Drought | Very Low | 2.62 / yr | $46 |
| Hail | Very Low | 0.03 / yr | $12K |
| Cold Wave | Very Low | 0.00 / yr | $149 |
| Coastal Flood | Very Low | 0.00 / yr | $0 |
| Hurricane | Very Low | 0.00 / yr | $0 |
| Tsunami | Very Low | 0.00 / yr | $0 |
Frequently Asked Questions
What is the overall natural disaster risk for Lewis County?
Lewis County has a composite FEMA National Risk Index score of 89.7 out of 100, placing it in the Medium category and the 90th national percentile. This combines Expected Annual Loss, Social Vulnerability, and Community Resilience across 18 hazard types.
What are the top natural hazards in Lewis County?
The three highest-rated hazards are Earthquake (Medium, $30M EAL), Landslide (Medium, $195K EAL), Volcanic Activity (Medium, $287K EAL). These account for most of the county's expected annual losses.
How does Lewis County compare to other Washington counties?
Lewis County ranks #15 of 39 Washington counties for overall natural disaster risk, with a medium 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. Lewis County's $71M EAL is a statistical average, not a guarantee for any specific year or address.