Natural disaster risk in Lemhi County, Idaho
Idaho · population 7,951 · FIPS 16059
Overall: very low risk
Lemhi County has a composite risk score of 41.4 out of 100 — higher than 41% of US counties. It ranks 20 of 44 in Idaho (1 = highest risk). Its highest-rated hazards are landslide, wildfire, lightning.
Drought now: Yes: D1 Moderate Drought, 29 weeks
Yes. On the U.S. Drought Monitor map valid 13 October 2026, 0.25% of Lemhi County is in D1 Moderate Drought. Some of it has been at D1 or worse for 29 weeks in a row.
Drought in Lemhi County: the last 52 weeks · droughtmonitor.unl.edu
The U.S. Drought Monitor is jointly produced by the National Drought Mitigation Center at the University of Nebraska-Lincoln, the United States Department of Agriculture, the National Oceanic and Atmospheric Administration and the National Aeronautics and Space Administration. Map courtesy of NDMC.
Risk, loss, vulnerability and resilience
| Measure | Rating and score |
|---|---|
| Overall risk Expected annual loss, adjusted for social vulnerability and community resilience. |
Very low 41.4 |
| Expected annual loss About $11.4 million a year, on average, across all 18 hazards. |
Very low 40.2 |
| Social vulnerability Higher means people may find it harder to prepare and recover. |
Relatively moderate 51.4 |
| Community resilience Higher means a stronger ability to prepare, adapt and recover. |
Very low 5 |
Risk by hazard
FEMA's risk rating for each of 18 natural hazards in Lemhi County, highest first. "Not applicable" means the hazard is not modelled here.
| Hazard | Risk rating and score |
|---|---|
| Landslide | Relatively moderate 95 |
| Wildfire | Relatively moderate 93 |
| Lightning | Relatively moderate 78 |
| Inland (riverine) flooding | Relatively low 59 |
| Cold wave | Relatively low 30 |
| Avalanche | Very low 60 |
| Earthquake | Very low 53 |
| Winter weather | Very low 21 |
| Drought | Very low 14 |
| Volcanic activity | Very low 13 |
| Heat wave | Very low 12 |
| Ice storm | Very low 6 |
| Hail | Very low 4 |
| Strong wind | Very low 4 |
| Tornado | Very low 3 |
| Coastal flooding | Not applicable |
| Hurricane | Not applicable |
| Tsunami | Not applicable |
FEMA disaster declarations for Lemhi County
Federal declarations that designated Lemhi County, since 1 Jan 2024 (the period this site keeps from OpenFEMA). Older declarations are in FEMA's own dataset.
Not since 1 Jan 2024: no FEMA disaster declaration in the records this site read names Lemhi County.
All FEMA declarations in Idaho, with estimated apply-by dates · Open FEMA deadlines
This product uses the Federal Emergency Management Agency's OpenFEMA API, but is not endorsed by FEMA. The Federal Government or FEMA cannot vouch for the data or analyses derived from these data after the data have been retrieved from the Agency's website(s). Dataset: Disaster Declarations Summaries - v2.
How to read these ratings
- Ratings run in five steps: very low, relatively low, relatively moderate, relatively high and very high. They compare a county with every other US county; they are not a measure of danger on their own.
- Scores run from 0 to 100 and are national percentiles. The bar shows the score: a score of 80 means a higher value than 80% of US counties.
- Overall risk combines the expected annual loss with social vulnerability and community resilience.
- Expected annual loss is the average yearly loss to buildings, people and agriculture the model expects from all 18 hazards.
- Social vulnerability describes how hard it may be for people to prepare for and recover from a disaster. Higher is worse.
- Community resilience describes a community's ability to prepare, adapt and recover. Higher is better.
- "Not applicable" means FEMA does not model that hazard there (for example, hurricanes far inland).
About this data
Source: FEMA National Risk Index, version 1.20, released December 2025, published by the Federal Emergency Management Agency (US public domain). About the National Risk Index. The index is a model of relative risk built from historical hazard records, what is exposed and community factors. It is not a forecast, it does not describe any single property, and it is not insurance or financial advice. For decisions about a specific address, check FEMA's flood maps and your local emergency management office.
Questions
What is the natural disaster risk in Lemhi County, Idaho?
FEMA's National Risk Index rates the overall risk in Lemhi County as very low, with a score of 41.4 out of 100 (higher than 41% of US counties). That is a comparison with other US counties, not a forecast.
What are the biggest natural hazards in Lemhi County?
The hazards rated highest for Lemhi County are landslide (relatively moderate), wildfire (relatively moderate), lightning (relatively moderate).
What is the flood risk in Lemhi County?
FEMA rates inland (river and rain) flooding risk in Lemhi County as relatively low. For a specific property, check the FEMA flood map and your local floodplain office.
Has Lemhi County had a FEMA disaster declaration?
Not since 1 Jan 2024: no FEMA disaster declaration in the records this site read names Lemhi County.
Is Lemhi County in a drought?
Yes. On the U.S. Drought Monitor map valid 13 October 2026, 0.25% of Lemhi County is in D1 Moderate Drought. Some of it has been at D1 or worse for 29 weeks in a row.
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