Colorado avalanche risk
Summit County has the highest avalanche risk in Colorado, scoring 99 out of 100 — rated "Very High" by FEMA's National Risk Index.
| # | County | NRI score | Rating |
|---|---|---|---|
| 1 | Summit County | 99 | Very High |
| 2 | Pitkin County | 98.8 | Very High |
| 3 | Clear Creek County | 98 | Very High |
| 4 | Eagle County | 96.3 | Very High |
| 5 | Gunnison County | 96.2 | Very High |
| 6 | Jackson County | 95.9 | Very High |
| 7 | San Juan County | 95.8 | Very High |
| 8 | Chaffee County | 95.3 | Very High |
| 9 | Grand County | 95 | Very High |
| 10 | San Miguel County | 93.7 | Relatively High |
| 11 | Ouray County | 93.3 | Relatively High |
| 12 | Dolores County | 92.3 | Relatively High |
| 13 | Rio Blanco County | 92 | Relatively High |
| 14 | Larimer County | 91.8 | Relatively High |
| 15 | Mineral County | 90.2 | Relatively High |
| 16 | Mesa County | 90.1 | Relatively High |
| 17 | Garfield County | 89.6 | Relatively High |
| 18 | Conejos County | 88.7 | Relatively High |
| 19 | Lake County | 88.6 | Relatively High |
| 20 | La Plata County | 88.5 | Relatively High |
| 21 | Rio Grande County | 88.3 | Relatively High |
| 22 | Montezuma County | 88.2 | Relatively High |
| 23 | Boulder County | 87.3 | Relatively High |
| 24 | Saguache County | 84.8 | Relatively Moderate |
| 25 | Routt County | 84.6 | Relatively Moderate |
| 26 | Alamosa County | 83.3 | Relatively Moderate |
| 27 | Montrose County | 79.7 | Relatively Moderate |
| 28 | Delta County | 79.5 | Relatively Moderate |
| 29 | El Paso County | 79.1 | Relatively Moderate |
| 30 | Hinsdale County | 78.7 | Relatively Moderate |
| 31 | Gilpin County | 78.1 | Relatively Low |
| 32 | Jefferson County | 77.9 | Relatively Low |
| 33 | Archuleta County | 77.8 | Relatively Low |
| 34 | Park County | 77.6 | Relatively Low |
| 35 | Las Animas County | 77.3 | Relatively Low |
| 36 | Moffat County | 61.7 | Very Low |
| 37 | Fremont County | 31.1 | Very Low |
| 38 | Costilla County | 29.5 | Very Low |
| 39 | Huerfano County | 25.9 | Very Low |
| 40 | Custer County | 22.2 | Very Low |
| 41 | Teller County | 12.9 | Very Low |
| 42 | Pueblo County | 10.4 | Very Low |
| 43 | Douglas County | 9.6 | 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.
Avalanche risk nationally:
Other hazard risks in Colorado:
Frequently asked questions
What is the highest avalanche risk county in Colorado?
Summit County, CO has the highest avalanche risk in Colorado, with a FEMA National Risk Index score of 99 out of 100 (rated "Very High").
How many counties in Colorado are rated Very High for avalanche risk?
9 of 43 scored Colorado counties are rated "Very High" for avalanche risk by FEMA's National Risk Index.
What causes avalanche risk in Colorado?
Avalanche risk reflects expected annual losses from snow avalanche events, primarily affecting mountain counties in the West. The highest scores belong to Colorado, Utah, Montana, and Washington counties where active ski terrain, mountain highways, and communities overlap with historically active avalanche paths and high seasonal snowpack. Avalanche events are reported at forecast-zone level in NOAA Storm Events and are not included in county-level counts.