Lewis County
Idaho — Natural Disaster Risk Assessment
Very LowComposite Risk Score
National percentile: 3th
Lewis County faces very low composite natural disaster risk (NRI Risk Index score 3.1, 3th national percentile), driven primarily by wildfire and avalanche exposure. Expected annual loss across all 18 hazard types is $2M.
Source: FEMA National Risk Index v1.20 · Updated December 2025
Top Hazards
All 18 Hazard Risks
| Wildfire | Low | 0.01 / yr | $628K |
| Avalanche | Very Low | 0.01 / yr | $2K |
| Landslide | Very Low | 0.19 / yr | $519 |
| Earthquake | Very Low | 0.00 / yr | $31K |
| Heat Wave | Very Low | 3.68 / yr | $47K |
| Drought | Very Low | 15.86 / yr | $608 |
| Riverine Flood | Very Low | 0.14 / yr | $1M |
| Cold Wave | Very Low | 0.26 / yr | $56K |
| Hail | Very Low | 0.32 / yr | $20K |
| Tornado | Very Low | 0.01 / yr | $5K |
| Winter Weather | Very Low | 19.95 / yr | $1K |
| Strong Wind | Very Low | 0.19 / yr | $11K |
| Lightning | Very Low | 18.53 / yr | $6K |
| Ice Storm | Very Low | 0.01 / yr | $419 |
| Coastal Flood | Very Low | 0.00 / yr | $0 |
| Hurricane | Very Low | 0.00 / yr | $0 |
| Tsunami | Very Low | 0.00 / yr | $0 |
| Volcanic Activity | 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 3.1 out of 100, placing it in the Very Low category and the 3th 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 Wildfire (Low, $628K EAL), Avalanche (Very Low, $2K EAL), Landslide (Very Low, $519 EAL). These account for most of the county's expected annual losses.
How does Lewis County compare to other Idaho counties?
Lewis County ranks #42 of 44 Idaho 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. Lewis County's $2M EAL is a statistical average, not a guarantee for any specific year or address.