Iowa ice storm risk
Polk County has the highest ice storm risk in Iowa, scoring 91.7 out of 100 — rated "Relatively High" by FEMA's National Risk Index.
| # | County | NRI score | Rating |
|---|---|---|---|
| 1 | Polk County | 91.7 | Relatively High |
| 2 | Linn County | 85.9 | Relatively High |
| 3 | Woodbury County | 85.6 | Relatively High |
| 4 | Scott County | 85.2 | Relatively High |
| 5 | Pottawattamie County | 81.1 | Relatively Moderate |
| 6 | Johnson County | 75.7 | Relatively Moderate |
| 7 | Muscatine County | 73 | Relatively Moderate |
| 8 | Sioux County | 71.8 | Relatively Moderate |
| 9 | Plymouth County | 70.3 | Relatively Moderate |
| 10 | Dickinson County | 70 | Relatively Moderate |
| 11 | Clinton County | 69.6 | Relatively Moderate |
| 12 | Dallas County | 68.5 | Relatively Moderate |
| 13 | Black Hawk County | 68.4 | Relatively Moderate |
| 14 | Lyon County | 67.9 | Relatively Moderate |
| 15 | Des Moines County | 67 | Relatively Moderate |
| 16 | Carroll County | 64.6 | Relatively Moderate |
| 17 | Story County | 64.2 | Relatively Moderate |
| 18 | Crawford County | 63.9 | Relatively Moderate |
| 19 | Audubon County | 62 | Relatively Moderate |
| 20 | Sac County | 56.7 | Relatively Low |
| 21 | Cass County | 56.4 | Relatively Low |
| 22 | Madison County | 55.9 | Relatively Low |
| 23 | Lee County | 55.7 | Relatively Low |
| 24 | Jasper County | 54.1 | Relatively Low |
| 25 | Webster County | 54.1 | Relatively Low |
| 26 | Harrison County | 53.7 | Relatively Low |
| 27 | Warren County | 51.3 | Relatively Low |
| 28 | Buena Vista County | 50.2 | Relatively Low |
| 29 | Marshall County | 50.1 | Relatively Low |
| 30 | Louisa County | 49.2 | Relatively Low |
| 31 | Dubuque County | 48.6 | Relatively Low |
| 32 | Cherokee County | 47.6 | Relatively Low |
| 33 | Washington County | 47 | Relatively Low |
| 34 | Calhoun County | 46.6 | Relatively Low |
| 35 | Cedar County | 45.5 | Relatively Low |
| 36 | Osceola County | 45.4 | Relatively Low |
| 37 | Benton County | 45.2 | Relatively Low |
| 38 | Wapello County | 45 | Relatively Low |
| 39 | Iowa County | 44.5 | Relatively Low |
| 40 | Mahaska County | 44.5 | Relatively Low |
| 41 | Monona County | 43.2 | Relatively Low |
| 42 | O'Brien County | 42.7 | Relatively Low |
| 43 | Poweshiek County | 42.6 | Relatively Low |
| 44 | Marion County | 42.5 | Relatively Low |
| 45 | Cerro Gordo County | 42.1 | Relatively Low |
| 46 | Tama County | 41.3 | Relatively Low |
| 47 | Page County | 41.2 | Relatively Low |
| 48 | Shelby County | 41.1 | Relatively Low |
| 49 | Hardin County | 40.9 | Relatively Low |
| 50 | Mills County | 40.6 | Relatively Low |
| 51 | Henry County | 40.5 | Relatively Low |
| 52 | Adair County | 40.3 | Relatively Low |
| 53 | Clay County | 39.4 | Relatively Low |
| 54 | Greene County | 39.3 | Relatively Low |
| 55 | Hamilton County | 39.2 | Relatively Low |
| 56 | Jefferson County | 39.2 | Relatively Low |
| 57 | Ida County | 38.7 | Relatively Low |
| 58 | Wayne County | 37.9 | Relatively Low |
| 59 | Boone County | 37.5 | Relatively Low |
| 60 | Union County | 36.9 | Relatively Low |
| 61 | Emmet County | 36.8 | Relatively Low |
| 62 | Montgomery County | 36.7 | Relatively Low |
| 63 | Jackson County | 35.8 | Relatively Low |
| 64 | Kossuth County | 35.7 | Relatively Low |
| 65 | Davis County | 35.6 | Relatively Low |
| 66 | Guthrie County | 35.1 | Relatively Low |
| 67 | Clarke County | 34.4 | Relatively Low |
| 68 | Pocahontas County | 33.9 | Relatively Low |
| 69 | Fayette County | 33.7 | Relatively Low |
| 70 | Wright County | 32.6 | Relatively Low |
| 71 | Fremont County | 32.3 | Relatively Low |
| 72 | Jones County | 31.3 | Relatively Low |
| 73 | Winneshiek County | 29.6 | Relatively Low |
| 74 | Humboldt County | 28.9 | Relatively Low |
| 75 | Appanoose County | 28.8 | Relatively Low |
| 76 | Delaware County | 28.7 | Relatively Low |
| 77 | Lucas County | 28.1 | Relatively Low |
| 78 | Floyd County | 27.9 | Relatively Low |
| 79 | Keokuk County | 27.2 | Relatively Low |
| 80 | Allamakee County | 27.1 | Relatively Low |
| 81 | Franklin County | 27 | Relatively Low |
| 82 | Bremer County | 26.2 | Very Low |
| 83 | Chickasaw County | 25.6 | Very Low |
| 84 | Palo Alto County | 25.6 | Very Low |
| 85 | Taylor County | 25.5 | Very Low |
| 86 | Hancock County | 24.9 | Very Low |
| 87 | Buchanan County | 24.3 | Very Low |
| 88 | Decatur County | 22.7 | Very Low |
| 89 | Winnebago County | 22.7 | Very Low |
| 90 | Clayton County | 21.6 | Very Low |
| 91 | Grundy County | 21.4 | Very Low |
| 92 | Mitchell County | 21.2 | Very Low |
| 93 | Howard County | 21.1 | Very Low |
| 94 | Butler County | 20.2 | Very Low |
| 95 | Monroe County | 19.5 | Very Low |
| 96 | Adams County | 18.9 | Very Low |
| 97 | Van Buren County | 17.9 | Very Low |
| 98 | Ringgold County | 16.7 | Very Low |
| 99 | Worth County | 14.2 | 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 Iowa:
Frequently asked questions
What is the highest ice storm risk county in Iowa?
Polk County, IA has the highest ice storm risk in Iowa, with a FEMA National Risk Index score of 91.7 out of 100 (rated "Relatively High").
What causes ice storm risk in Iowa?
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.