Natural disaster risk in Idaho, by county
All 44 counties in Idaho, ranked by FEMA's National Risk Index composite risk score, with each one's highest-rated hazard. Other states
At a glance
Highest overall risk: Ada County (relatively moderate, score 87.8). Lowest: Clark County (very low, score 0.8).
Top hazards in Idaho
| Hazard | Counties rated relatively high or very high | Average score |
|---|---|---|
| Avalanche | 12 of 44 | 61.4 |
| Winter weather | 9 of 44 | 59.2 |
| Lightning | 4 of 44 | 35.0 |
| Wildfire | 3 of 44 | 85.7 |
| Landslide | 3 of 44 | 64.1 |
All counties, highest risk first
| # | County | Overall risk | Highest-rated hazard |
|---|---|---|---|
| 1 | Ada County | Relatively moderate 87.8 | Winter weather (very high) |
| 2 | Bonneville County | Relatively moderate 82.4 | Avalanche (relatively high) |
| 3 | Kootenai County | Relatively low 79 | Winter weather (relatively high) |
| 4 | Idaho County | Relatively low 78.4 | Landslide (relatively high) |
| 5 | Bonner County | Relatively low 77.3 | Avalanche (relatively high) |
| 6 | Canyon County | Relatively low 71.7 | Winter weather (very high) |
| 7 | Bannock County | Relatively low 66.9 | Winter weather (relatively high) |
| 8 | Blaine County | Relatively low 65.4 | Avalanche (very high) |
| 9 | Shoshone County | Relatively low 62.8 | Avalanche (very high) |
| 10 | Bingham County | Relatively low 60.1 | Winter weather (relatively high) |
| 11 | Madison County | Relatively low 58.6 | Lightning (relatively high) |
| 12 | Valley County | Relatively low 55.6 | Wildfire (relatively moderate) |
| 13 | Custer County | Relatively low 52.4 | Avalanche (very high) |
| 14 | Elmore County | Relatively low 52 | Wildfire (relatively high) |
| 15 | Boise County | Relatively low 48.9 | Avalanche (relatively high) |
| 16 | Clearwater County | Relatively low 46.9 | Landslide (relatively moderate) |
| 17 | Twin Falls County | Relatively low 46.9 | Winter weather (relatively high) |
| 18 | Owyhee County | Relatively low 44.1 | Wildfire (relatively moderate) |
| 19 | Cassia County | Relatively low 43.6 | Wildfire (relatively moderate) |
| 20 | Lemhi County | Very low 41.4 | Landslide (relatively moderate) |
| 21 | Jefferson County | Very low 40.1 | Winter weather (relatively moderate) |
| 22 | Adams County | Very low 39.6 | Avalanche (relatively high) |
| 23 | Fremont County | Very low 38.3 | Avalanche (relatively high) |
| 24 | Gem County | Very low 34.4 | Wildfire (relatively moderate) |
| 25 | Latah County | Very low 33.3 | Wildfire (relatively moderate) |
| 26 | Nez Perce County | Very low 33 | Wildfire (relatively moderate) |
| 27 | Washington County | Very low 30.3 | Wildfire (relatively moderate) |
| 28 | Teton County | Very low 29.5 | Avalanche (relatively high) |
| 29 | Boundary County | Very low 26.1 | Landslide (relatively moderate) |
| 30 | Gooding County | Very low 25.4 | Wildfire (relatively moderate) |
| 31 | Jerome County | Very low 21.5 | Winter weather (relatively high) |
| 32 | Minidoka County | Very low 20.5 | Winter weather (relatively moderate) |
| 33 | Benewah County | Very low 19.9 | Landslide (relatively moderate) |
| 34 | Payette County | Very low 17.1 | Wildfire (relatively moderate) |
| 35 | Power County | Very low 16.9 | Wildfire (relatively moderate) |
| 36 | Lincoln County | Very low 9.1 | Wildfire (relatively moderate) |
| 37 | Franklin County | Very low 7.6 | Winter weather (relatively moderate) |
| 38 | Caribou County | Very low 7.2 | Avalanche (relatively moderate) |
| 39 | Bear Lake County | Very low 6.6 | Avalanche (relatively moderate) |
| 40 | Camas County | Very low 6 | Avalanche (relatively high) |
| 41 | Butte County | Very low 4.4 | Avalanche (relatively moderate) |
| 42 | Lewis County | Very low 3.1 | Wildfire (relatively low) |
| 43 | Oneida County | Very low 1.4 | Wildfire (relatively low) |
| 44 | Clark County | Very low 0.8 | Avalanche (relatively moderate) |
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
Which county in Idaho has the highest natural disaster risk?
Ada County has the highest composite risk score in Idaho in FEMA's National Risk Index: 87.8, rated relatively moderate.
Which county in Idaho has the lowest natural disaster risk?
Clark County has the lowest composite risk score in Idaho: 0.8, rated very low. A low score means lower modelled risk compared with other US counties, not no risk.
What natural disasters is Idaho most at risk from?
Across Idaho, the hazards rated highest in the most counties are avalanche, winter weather, lightning, according to FEMA's National Risk Index. Each county page lists all 18 hazards.
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