North Dakota ice storm risk
Cass County has the highest ice storm risk in North Dakota, scoring 96 out of 100 — rated "Very High" by FEMA's National Risk Index.
| # | County | NRI score | Rating |
|---|---|---|---|
| 1 | Cass County | 96 | Very High |
| 2 | Burleigh County | 95.5 | Very High |
| 3 | Grand Forks County | 91.8 | Relatively High |
| 4 | Rolette County | 89.2 | Relatively High |
| 5 | Williams County | 86.3 | Relatively High |
| 6 | Stutsman County | 85.9 | Relatively High |
| 7 | Ward County | 85.5 | Relatively High |
| 8 | Morton County | 85 | Relatively High |
| 9 | Walsh County | 83 | Relatively High |
| 10 | Benson County | 82 | Relatively Moderate |
| 11 | Barnes County | 81.5 | Relatively Moderate |
| 12 | McLean County | 81 | Relatively Moderate |
| 13 | Nelson County | 79.6 | Relatively Moderate |
| 14 | Ramsey County | 78.9 | Relatively Moderate |
| 15 | Pembina County | 78.2 | Relatively Moderate |
| 16 | Cavalier County | 77.5 | Relatively Moderate |
| 17 | Stark County | 76.8 | Relatively Moderate |
| 18 | Bottineau County | 76.7 | Relatively Moderate |
| 19 | McHenry County | 76.4 | Relatively Moderate |
| 20 | Ransom County | 75.9 | Relatively Moderate |
| 21 | Traill County | 75.2 | Relatively Moderate |
| 22 | Griggs County | 74.4 | Relatively Moderate |
| 23 | McKenzie County | 70.9 | Relatively Moderate |
| 24 | Emmons County | 70.6 | Relatively Moderate |
| 25 | Hettinger County | 70.6 | Relatively Moderate |
| 26 | Steele County | 70.4 | Relatively Moderate |
| 27 | Sheridan County | 70 | Relatively Moderate |
| 28 | Mountrail County | 69.5 | Relatively Moderate |
| 29 | Towner County | 69.5 | Relatively Moderate |
| 30 | Sargent County | 68.5 | Relatively Moderate |
| 31 | Eddy County | 68 | Relatively Moderate |
| 32 | Divide County | 67.1 | Relatively Moderate |
| 33 | Mercer County | 65 | Relatively Moderate |
| 34 | Grant County | 61.6 | Relatively Moderate |
| 35 | Richland County | 61.1 | Relatively Moderate |
| 36 | LaMoure County | 60.8 | Relatively Moderate |
| 37 | Dunn County | 60.1 | Relatively Moderate |
| 38 | Wells County | 60 | Relatively Low |
| 39 | McIntosh County | 58.1 | Relatively Low |
| 40 | Foster County | 56.8 | Relatively Low |
| 41 | Dickey County | 55.5 | Relatively Low |
| 42 | Pierce County | 51.9 | Relatively Low |
| 43 | Kidder County | 48.1 | Relatively Low |
| 44 | Sioux County | 46.8 | Relatively Low |
| 45 | Bowman County | 40 | Relatively Low |
| 46 | Logan County | 37.5 | Relatively Low |
| 47 | Renville County | 36.7 | Relatively Low |
| 48 | Adams County | 36.1 | Relatively Low |
| 49 | Golden Valley County | 34.7 | Relatively Low |
| 50 | Burke County | 34.1 | Relatively Low |
| 51 | Oliver County | 32.5 | Relatively Low |
| 52 | Billings County | 23 | Very Low |
| 53 | Slope County | 14.3 | 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 North Dakota:
Frequently asked questions
What is the highest ice storm risk county in North Dakota?
Cass County, ND has the highest ice storm risk in North Dakota, with a FEMA National Risk Index score of 96 out of 100 (rated "Very High").
How many counties in North Dakota are rated Very High for ice storm risk?
2 of 53 scored North Dakota counties are rated "Very High" for ice storm risk by FEMA's National Risk Index.
What causes ice storm risk in North Dakota?
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.