Idaho winter weather risk

44 counties scored 2 rated Very High

Ada County has the highest winter weather risk in Idaho, scoring 98.9 out of 100 — rated "Very High" by FEMA's National Risk Index.

# County NRI score Rating NOAA events
2016–2026
1 Ada County 98.9 Very High 0
2 Canyon County 97 Very High 0
3 Bannock County 96.1 Relatively High 0
4 Twin Falls County 95.2 Relatively High 0
5 Bingham County 93.4 Relatively High 0
6 Blaine County 93.1 Relatively High 0
7 Kootenai County 92.7 Relatively High 0
8 Bonner County 86.5 Relatively High 0
9 Jerome County 86.3 Relatively High 0
10 Jefferson County 82.7 Relatively Moderate 0
11 Minidoka County 82.3 Relatively Moderate 0
12 Cassia County 81.9 Relatively Moderate 0
13 Fremont County 78.5 Relatively Moderate 0
14 Gooding County 71.5 Relatively Moderate 0
15 Owyhee County 71.2 Relatively Moderate 0
16 Power County 70.9 Relatively Moderate 0
17 Elmore County 69.6 Relatively Moderate 0
18 Boundary County 68.4 Relatively Moderate 0
19 Madison County 67.9 Relatively Moderate 0
20 Bonneville County 66.2 Relatively Moderate 0
21 Teton County 64.6 Relatively Moderate 0
22 Franklin County 64.3 Relatively Moderate 0
23 Shoshone County 61.9 Relatively Moderate 0
24 Valley County 59.1 Relatively Low 0
25 Caribou County 58.6 Relatively Low 0
26 Payette County 58.3 Relatively Low 0
27 Bear Lake County 55 Relatively Low 0
28 Gem County 53.9 Relatively Low 0
29 Boise County 51.9 Relatively Low 0
30 Lincoln County 51.6 Relatively Low 0
31 Washington County 51.6 Relatively Low 0
32 Custer County 50.4 Relatively Low 0
33 Adams County 41 Relatively Low 0
34 Idaho County 40.5 Relatively Low 0
35 Benewah County 37.2 Relatively Low 0
36 Oneida County 37.1 Relatively Low 0
37 Clearwater County 34 Relatively Low 0
38 Butte County 33.1 Relatively Low 0
39 Lemhi County 21.9 Very Low 0
40 Clark County 14.6 Very Low 0
41 Latah County 14.3 Very Low 0
42 Camas County 14.2 Very Low 0
43 Nez Perce County 5.5 Very Low 0
44 Lewis County 2.8 Very Low 0

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.

Winter Weather risk nationally:

Other hazard risks in Idaho:

Frequently asked questions

What is the highest winter weather risk county in Idaho?

Ada County, ID has the highest winter weather risk in Idaho, with a FEMA National Risk Index score of 98.9 out of 100 (rated "Very High").

How many counties in Idaho are rated Very High for winter weather risk?

2 of 44 scored Idaho counties are rated "Very High" for winter weather risk by FEMA's National Risk Index.

What causes winter weather risk in Idaho?

Winter weather risk captures expected losses from heavy snow, blizzards, and mixed precipitation. Highest scores appear in the Great Lakes snowbelt, northern Rockies, and interior Northeast, where lake-effect and orographic snowfall is frequent. Winter weather impacts transportation networks, utilities, agriculture, and population health.