Lemhi County
Idaho — Natural Disaster Risk Assessment
Very LowComposite Risk Score
National percentile: 41th
Lemhi County faces very low composite natural disaster risk (NRI Risk Index score 41.4, 41th national percentile), driven primarily by landslide and wildfire exposure. Expected annual loss across all 18 hazard types is $11M.
Source: FEMA National Risk Index v1.20 · Updated December 2025
Top Hazards
All 18 Hazard Risks
| Landslide | Medium | 4.10 / yr | $139K |
| Wildfire | Medium | 0.00 / yr | $2M |
| Lightning | Medium | 31.11 / yr | $591K |
| Avalanche | Very Low | 0.01 / yr | $1K |
| Riverine Flood | Low | 0.64 / yr | $8M |
| Earthquake | Very Low | 0.02 / yr | $288K |
| Cold Wave | Low | 0.96 / yr | $383K |
| Winter Weather | Very Low | 27.98 / yr | $17K |
| Drought | Very Low | 68.80 / yr | $355 |
| Volcanic Activity | Very Low | 0.00 / yr | $0 |
| Heat Wave | Very Low | 0.37 / yr | $23K |
| Ice Storm | Very Low | 0.01 / yr | $3K |
| Hail | Very Low | 0.14 / yr | $10K |
| Strong Wind | Very Low | 0.20 / yr | $25K |
| Tornado | Very Low | 0.10 / yr | $7K |
| 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 Lemhi County?
Lemhi County has a composite FEMA National Risk Index score of 41.4 out of 100, placing it in the Very Low category and the 41th national percentile. This combines Expected Annual Loss, Social Vulnerability, and Community Resilience across 18 hazard types.
What are the top natural hazards in Lemhi County?
The three highest-rated hazards are Landslide (Medium, $139K EAL), Wildfire (Medium, $2M EAL), Lightning (Medium, $591K EAL). These account for most of the county's expected annual losses.
How does Lemhi County compare to other Idaho counties?
Lemhi County ranks #20 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. Lemhi County's $11M EAL is a statistical average, not a guarantee for any specific year or address.