Lemhi County, ID
FEMA National Risk Index scores, disaster declarations & hazard data
Lemhi County has experienced 5 federally declared disasters since 1984, most recently Covid-19 in 2020. Its overall natural hazard risk is rated Very Low — among the lowest-risk counties in the country.
Lemhi County's highest-rated hazards are landslide, wildfire, and lightning, with its top risk rated "Relatively Moderate" by FEMA's National Risk Index.
Past disasters & FEMA designations
A federal disaster declaration officially designates a county for FEMA disaster assistance. Lemhi County has been designated in 5 declarations since 1984, covering 4 disaster types including biological (2), hurricane (1), fire (1).
| Year | Type | Event name |
|---|---|---|
| 2020 | Biological | Covid-19 Pandemic |
| 2020 | Biological | Covid-19 |
| 2005 | Hurricane | Hurricane Katrina |
| 2000 | Fire | Wildfires |
| 1984 | Snowstorm | Ice Jams And Flooding |
Source: FEMA OpenFEMA Disaster Declarations Summaries. A single disaster can produce more than one record per county. Data current through September 2026.
Risk by hazard type
| Hazard | Risk rating | Risk score | Recorded events | Deaths | Prop. damage |
|---|---|---|---|---|---|
| Wildfire | Relatively Moderate | 93.2 | 0 | 0 | — |
| Inland Flooding | Relatively Low | 59.8 | 8 | 0 | $260K |
| Coastal Flooding | Not Applicable | — | 0 | 0 | — |
| Earthquake | Very Low | 53.5 | 21 | — | — |
| Heat Wave | Very Low | 12.5 | 1 | 0 | — |
| Tornado | Very Low | 3.1 | 0 | 0 | — |
| Hurricane | Not Applicable | — | 0 | 0 | — |
| Hail | Very Low | 4.8 | 5 | 0 | $12K |
| Strong Wind | Very Low | 4.3 | 0 | 0 | — |
| Winter Weather | Very Low | 21.9 | 0 | 0 | — |
| Ice Storm | Very Low | 6.9 | — | — | — |
| Cold Wave | Relatively Low | 30.7 | — | — | — |
| Lightning | Relatively Moderate | 78.3 | 0 | 0 | — |
| Drought | Very Low | 14.4 | 0 | 0 | — |
| Landslide | Relatively Moderate | 95.7 | 6 | 0 | $5K |
| Avalanche | Very Low | 60.1 | — | — | — |
| Tsunami | Not Applicable | — | — | — | — |
| Volcanic Activity | Very Low | 13 | — | — | — |
Scores are 0–100 percentiles relative to all US counties — higher means more exposed, not that a disaster is likely this year. Event counts: NOAA Storm Events 2016–2026; earthquake counts from USGS ComCat (M3.0+, 1996–2026). See the methodology page for details.
Community vulnerability
Lemhi County ranks in the 41st percentile (Low) for community vulnerability — a measure of how hard disaster impacts tend to hit residents. Higher vulnerability means more displacement, worse health outcomes, and slower recovery after a disaster.
| SVI theme | Percentile | Vulnerability level |
|---|---|---|
| Overall | 41st | Low |
| Socioeconomic status | 36th | Low |
| Household characteristics | 56th | Moderate |
| Racial & ethnic minority status | 20th | Very low |
| Housing type & transportation | 52nd | Moderate |
Source: CDC/ATSDR Social Vulnerability Index 2022. Percentiles compare counties nationally — higher means more vulnerable relative to other counties. See CDC SVI for full methodology.
Future risk outlook
| Wildfire metric | National percentile | Level |
|---|---|---|
| Burn probability | 91st | Very High |
| Risk to homes | 93rd | Very High |
| Buildings in direct exposure zone | 71.0% | — |
Wildfire: USDA Forest Service Wildfire Risk to Communities (RDS-2020-0016-2) — modeled values, not annual forecasts. See wildfirerisk.org. Inland flood and heat projections pending data availability; coastal sea-level projections are available for select coastal counties below — see the data page.
Nearby counties
Frequently asked questions
What natural hazards pose the greatest risk in Lemhi County?
According to the FEMA National Risk Index, the highest-risk hazards in Lemhi County, Idaho are landslide, wildfire, and lightning. The county's overall natural hazard risk is rated Very Low — among the lowest-risk counties in the country.
Has Lemhi County received federal disaster declarations?
Yes. Lemhi County has received 5 federal disaster declarations since 1984, including declarations in 2020. The most common disaster type on record is biological (2 declarations).
Has Lemhi County had any FEMA disaster declarations in 2024, 2025, or 2026?
No federal disaster declarations have been recorded for Lemhi County since the start of 2024. Its most recent declaration on record is Covid-19 in 2020.
How does Lemhi County's natural hazard risk compare to nearby counties?
Among neighboring counties, Ravalli County, MT has the highest overall natural hazard risk (Relatively Low) and Clark County, ID has the lowest (Very Low). Lemhi County is rated Very Low overall.
How is Lemhi County's composite disaster risk index calculated?
Lemhi County's composite disaster risk index — officially FEMA's National Risk Index (NRI) — scores every US county on a 0–100 percentile scale across 18 natural hazard types, factoring in expected annual loss, social vulnerability, and community resilience. Lemhi County's composite score of 41 means its overall natural hazard risk is higher than 41% of US counties.