Alaska avalanche risk
Matanuska-Susitna Borough has the highest avalanche risk in Alaska, scoring 99.9 out of 100 — rated "Very High" by FEMA's National Risk Index.
| # | County | NRI score | Rating |
|---|---|---|---|
| 1 | Matanuska-Susitna Borough | 99.9 | Very High |
| 2 | Kenai Peninsula Borough | 99.7 | Very High |
| 3 | Copper River Census Area | 99.4 | Very High |
| 4 | Denali Borough | 97.2 | Very High |
| 5 | Anchorage Municipality | 97.1 | Very High |
| 6 | Hoonah-Angoon Census Area | 95.6 | Very High |
| 7 | Chugach Census Area | 94.7 | Very High |
| 8 | Southeast Fairbanks Census Area | 94.4 | Relatively High |
| 9 | Petersburg Borough | 92.7 | Relatively High |
| 10 | Haines Borough | 89.2 | Relatively High |
| 11 | Sitka City and Borough | 85.2 | Relatively Moderate |
| 12 | Juneau City and Borough | 84.5 | Relatively Moderate |
| 13 | Yukon-Koyukuk Census Area | 84.1 | Relatively Moderate |
| 14 | Yakutat City and Borough | 83.9 | Relatively Moderate |
| 15 | Ketchikan Gateway Borough | 80.4 | Relatively Moderate |
| 16 | Aleutians West Census Area | 80.1 | Relatively Moderate |
| 17 | Fairbanks North Star Borough | 79.2 | Relatively Moderate |
| 18 | Lake and Peninsula Borough | 76.2 | Relatively Low |
| 19 | Bethel Census Area | 74.7 | Relatively Low |
| 20 | Dillingham Census Area | 72.4 | Relatively Low |
| 21 | Wrangell City and Borough | 70.9 | Relatively Low |
| 22 | Skagway Municipality | 68 | Relatively Low |
| 23 | Aleutians East Borough | 65.1 | Very Low |
| 24 | Northwest Arctic Borough | 62.6 | Very Low |
| 25 | North Slope Borough | 60.4 | Very Low |
| 26 | Nome Census Area | 58.8 | Very Low |
| 27 | Kodiak Island Borough | 50 | Very Low |
| 28 | Prince of Wales-Hyder Census Area | 39.5 | Very Low |
| 29 | Kusilvak Census Area | 17.5 | 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 Alaska:
Frequently asked questions
What is the highest avalanche risk county in Alaska?
Matanuska-Susitna Borough, AK has the highest avalanche risk in Alaska, with a FEMA National Risk Index score of 99.9 out of 100 (rated "Very High").
How many counties in Alaska are rated Very High for avalanche risk?
7 of 29 scored Alaska counties are rated "Very High" for avalanche risk by FEMA's National Risk Index.
What causes avalanche risk in Alaska?
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.