Idaho ice storm risk
Kootenai County has the highest ice storm risk in Idaho, scoring 84.1 out of 100 — rated "Relatively High" by FEMA's National Risk Index.
| # | County | NRI score | Rating |
|---|---|---|---|
| 1 | Kootenai County | 84.1 | Relatively High |
| 2 | Ada County | 80.5 | Relatively Moderate |
| 3 | Canyon County | 73.8 | Relatively Moderate |
| 4 | Bonner County | 71.3 | Relatively Moderate |
| 5 | Twin Falls County | 56.8 | Relatively Low |
| 6 | Shoshone County | 55.2 | Relatively Low |
| 7 | Benewah County | 40.4 | Relatively Low |
| 8 | Jerome County | 36.5 | Relatively Low |
| 9 | Elmore County | 30.4 | Relatively Low |
| 10 | Bonneville County | 26.8 | Very Low |
| 11 | Gooding County | 25.1 | Very Low |
| 12 | Gem County | 23.4 | Very Low |
| 13 | Owyhee County | 20.5 | Very Low |
| 14 | Bannock County | 20.3 | Very Low |
| 15 | Bingham County | 16.9 | Very Low |
| 16 | Madison County | 16.7 | Very Low |
| 17 | Latah County | 16.3 | Very Low |
| 18 | Washington County | 15.9 | Very Low |
| 19 | Cassia County | 13.8 | Very Low |
| 20 | Boise County | 13.2 | Very Low |
| 21 | Lincoln County | 12.4 | Very Low |
| 22 | Minidoka County | 11.5 | Very Low |
| 23 | Payette County | 11.1 | Very Low |
| 24 | Idaho County | 11 | Very Low |
| 25 | Jefferson County | 10.9 | Very Low |
| 26 | Blaine County | 9.2 | Very Low |
| 27 | Valley County | 9.2 | Very Low |
| 28 | Fremont County | 8.7 | Very Low |
| 29 | Teton County | 8.5 | Very Low |
| 30 | Clearwater County | 8.3 | Very Low |
| 31 | Custer County | 7.7 | Very Low |
| 32 | Nez Perce County | 7.1 | Very Low |
| 33 | Lemhi County | 6.9 | Very Low |
| 34 | Power County | 5.7 | Very Low |
| 35 | Franklin County | 5.5 | Very Low |
| 36 | Caribou County | 4.6 | Very Low |
| 37 | Bear Lake County | 3.8 | Very Low |
| 38 | Butte County | 3.1 | Very Low |
| 39 | Adams County | 2.7 | Very Low |
| 40 | Oneida County | 2.2 | Very Low |
| 41 | Lewis County | 1.2 | Very Low |
| 42 | Boundary County | 1 | Very Low |
| 43 | Camas County | 1 | Very Low |
| 44 | Clark County | 0.3 | Very Low |
Source: FEMA National Risk Index v1.20.0, December 2025. Scores are 0–100 percentile rankings among all US counties. See the methodology page for definitions. Download the full CSV for all counties.
Ice Storm risk nationally:
Other hazard risks in Idaho:
Frequently asked questions
What is the highest ice storm risk county in Idaho?
Kootenai County, ID has the highest ice storm risk in Idaho, with a FEMA National Risk Index score of 84.1 out of 100 (rated "Relatively High").
What causes ice storm risk in Idaho?
Ice storm risk covers damaging freezing rain and sleet accumulation, which collapses power lines, trees, and structures. The highest-risk counties cluster in a band from eastern Texas and Arkansas through the Carolinas and New England, where warm Gulf moisture overruns cold arctic air most frequently. Ice storms cause catastrophic and long-lasting power outages. Ice storm and sleet events are reported at forecast-zone level in NOAA Storm Events and are not included in county-level counts.