Montana cold wave risk
Cascade County has the highest cold wave risk in Montana, scoring 98 out of 100 — rated "Relatively High" by FEMA's National Risk Index.
| # | County | NRI score | Rating |
|---|---|---|---|
| 1 | Cascade County | 98 | Relatively High |
| 2 | Dawson County | 97.5 | Relatively High |
| 3 | Yellowstone County | 97.1 | Relatively High |
| 4 | Richland County | 95.5 | Relatively High |
| 5 | Flathead County | 95.1 | Relatively High |
| 6 | Roosevelt County | 95 | Relatively High |
| 7 | Lewis and Clark County | 94.6 | Relatively High |
| 8 | Hill County | 93.7 | Relatively High |
| 9 | Gallatin County | 93.6 | Relatively High |
| 10 | Missoula County | 93.1 | Relatively High |
| 11 | Fergus County | 91.8 | Relatively High |
| 12 | Glacier County | 91.7 | Relatively High |
| 13 | Blaine County | 90 | Relatively High |
| 14 | Ravalli County | 87.6 | Relatively Moderate |
| 15 | Custer County | 87 | Relatively Moderate |
| 16 | Phillips County | 85.9 | Relatively Moderate |
| 17 | Lake County | 85.8 | Relatively Moderate |
| 18 | Valley County | 85.7 | Relatively Moderate |
| 19 | Wibaux County | 82.3 | Relatively Moderate |
| 20 | Silver Bow County | 81.9 | Relatively Moderate |
| 21 | Chouteau County | 81.3 | Relatively Moderate |
| 22 | Pondera County | 81.3 | Relatively Moderate |
| 23 | Sheridan County | 79.5 | Relatively Moderate |
| 24 | Rosebud County | 78.5 | Relatively Moderate |
| 25 | Big Horn County | 76.9 | Relatively Moderate |
| 26 | Toole County | 76.6 | Relatively Moderate |
| 27 | Lincoln County | 72.8 | Relatively Moderate |
| 28 | Beaverhead County | 70 | Relatively Moderate |
| 29 | Park County | 69.8 | Relatively Moderate |
| 30 | Teton County | 68.7 | Relatively Moderate |
| 31 | Fallon County | 67.9 | Relatively Moderate |
| 32 | Sanders County | 66.5 | Relatively Moderate |
| 33 | Musselshell County | 65.5 | Relatively Moderate |
| 34 | Liberty County | 64.7 | Relatively Low |
| 35 | Prairie County | 64.2 | Relatively Low |
| 36 | Carbon County | 62.8 | Relatively Low |
| 37 | McCone County | 62.8 | Relatively Low |
| 38 | Jefferson County | 62.7 | Relatively Low |
| 39 | Deer Lodge County | 62 | Relatively Low |
| 40 | Powell County | 57.4 | Relatively Low |
| 41 | Judith Basin County | 56 | Relatively Low |
| 42 | Broadwater County | 54.3 | Relatively Low |
| 43 | Daniels County | 54.2 | Relatively Low |
| 44 | Madison County | 53.9 | Relatively Low |
| 45 | Garfield County | 44.1 | Relatively Low |
| 46 | Stillwater County | 43.4 | Relatively Low |
| 47 | Carter County | 39.3 | Relatively Low |
| 48 | Wheatland County | 37.5 | Relatively Low |
| 49 | Meagher County | 37 | Relatively Low |
| 50 | Granite County | 34.4 | Relatively Low |
| 51 | Petroleum County | 32.4 | Relatively Low |
| 52 | Powder River County | 32.3 | Relatively Low |
| 53 | Sweet Grass County | 29.8 | Relatively Low |
| 54 | Mineral County | 26.8 | Relatively Low |
| 55 | Golden Valley County | 20.4 | Very Low |
| 56 | Treasure County | 18.1 | 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.
Cold Wave risk nationally:
Other hazard risks in Montana:
Frequently asked questions
What is the highest cold wave risk county in Montana?
Cascade County, MT has the highest cold wave risk in Montana, with a FEMA National Risk Index score of 98 out of 100 (rated "Relatively High").
What causes cold wave risk in Montana?
Cold wave risk captures expected losses from extended periods of extreme cold, including wind chill. The northern Plains, Great Lakes, and interior New England see the most severe and frequent cold events. Cold extremes cause significant excess mortality, especially among unhoused populations, the elderly, and those with inadequate heating or insulation. Cold and wind chill events are reported at forecast-zone level in NOAA Storm Events and are not included in county-level counts.