Iowa cold wave risk
Polk County has the highest cold wave risk in Iowa, scoring 91.3 out of 100 — rated "Relatively High" by FEMA's National Risk Index.
| # | County | NRI score | Rating |
|---|---|---|---|
| 1 | Polk County | 91.3 | Relatively High |
| 2 | Johnson County | 90.3 | Relatively High |
| 3 | Adair County | 88.1 | Relatively Moderate |
| 4 | Woodbury County | 87.1 | Relatively Moderate |
| 5 | Cass County | 86.9 | Relatively Moderate |
| 6 | Emmet County | 86.2 | Relatively Moderate |
| 7 | Union County | 84.5 | Relatively Moderate |
| 8 | Linn County | 83.9 | Relatively Moderate |
| 9 | Scott County | 80.7 | Relatively Moderate |
| 10 | Pottawattamie County | 78.9 | Relatively Moderate |
| 11 | Dubuque County | 77.8 | Relatively Moderate |
| 12 | Cerro Gordo County | 74.5 | Relatively Moderate |
| 13 | Kossuth County | 70.8 | Relatively Moderate |
| 14 | Audubon County | 68.1 | Relatively Moderate |
| 15 | Black Hawk County | 67.7 | Relatively Moderate |
| 16 | Page County | 67.3 | Relatively Moderate |
| 17 | Crawford County | 66.4 | Relatively Moderate |
| 18 | Hancock County | 66.4 | Relatively Moderate |
| 19 | Clinton County | 66.1 | Relatively Moderate |
| 20 | Greene County | 65.7 | Relatively Moderate |
| 21 | Winnebago County | 65.5 | Relatively Moderate |
| 22 | Allamakee County | 65.2 | Relatively Low |
| 23 | Montgomery County | 64.2 | Relatively Low |
| 24 | Wright County | 63.2 | Relatively Low |
| 25 | Palo Alto County | 62.3 | Relatively Low |
| 26 | Buena Vista County | 61.7 | Relatively Low |
| 27 | Sioux County | 60.9 | Relatively Low |
| 28 | Taylor County | 60.9 | Relatively Low |
| 29 | Calhoun County | 60.3 | Relatively Low |
| 30 | Clarke County | 59.6 | Relatively Low |
| 31 | Carroll County | 59.2 | Relatively Low |
| 32 | Dallas County | 58.6 | Relatively Low |
| 33 | Hamilton County | 58.5 | Relatively Low |
| 34 | Lucas County | 58 | Relatively Low |
| 35 | Jackson County | 57.1 | Relatively Low |
| 36 | Fayette County | 56.9 | Relatively Low |
| 37 | Adams County | 56.4 | Relatively Low |
| 38 | Humboldt County | 56.4 | Relatively Low |
| 39 | Pocahontas County | 55.4 | Relatively Low |
| 40 | Decatur County | 55.1 | Relatively Low |
| 41 | Hardin County | 55 | Relatively Low |
| 42 | Delaware County | 54.9 | Relatively Low |
| 43 | Clayton County | 54.7 | Relatively Low |
| 44 | Winneshiek County | 54.7 | Relatively Low |
| 45 | Shelby County | 54.3 | Relatively Low |
| 46 | Franklin County | 53.6 | Relatively Low |
| 47 | Dickinson County | 52.9 | Relatively Low |
| 48 | Plymouth County | 52.3 | Relatively Low |
| 49 | Tama County | 51 | Relatively Low |
| 50 | Floyd County | 50.8 | Relatively Low |
| 51 | Osceola County | 50.7 | Relatively Low |
| 52 | Appanoose County | 50 | Relatively Low |
| 53 | Cherokee County | 49.5 | Relatively Low |
| 54 | Warren County | 47.6 | Relatively Low |
| 55 | O'Brien County | 47.3 | Relatively Low |
| 56 | Sac County | 45.9 | Relatively Low |
| 57 | Washington County | 45.8 | Relatively Low |
| 58 | Butler County | 45.7 | Relatively Low |
| 59 | Madison County | 45.2 | Relatively Low |
| 60 | Wayne County | 44.5 | Relatively Low |
| 61 | Chickasaw County | 42.8 | Relatively Low |
| 62 | Clay County | 42.8 | Relatively Low |
| 63 | Ringgold County | 42.5 | Relatively Low |
| 64 | Boone County | 42.1 | Relatively Low |
| 65 | Lyon County | 41.8 | Relatively Low |
| 66 | Muscatine County | 41.4 | Relatively Low |
| 67 | Marshall County | 41.2 | Relatively Low |
| 68 | Poweshiek County | 39.5 | Relatively Low |
| 69 | Worth County | 38.2 | Relatively Low |
| 70 | Ida County | 37 | Relatively Low |
| 71 | Des Moines County | 36.6 | Relatively Low |
| 72 | Davis County | 36.4 | Relatively Low |
| 73 | Bremer County | 36 | Relatively Low |
| 74 | Lee County | 35.8 | Relatively Low |
| 75 | Story County | 35.3 | Relatively Low |
| 76 | Jones County | 35.1 | Relatively Low |
| 77 | Mahaska County | 34.7 | Relatively Low |
| 78 | Webster County | 33.9 | Relatively Low |
| 79 | Monona County | 33.6 | Relatively Low |
| 80 | Jasper County | 32.2 | Relatively Low |
| 81 | Mitchell County | 32.1 | Relatively Low |
| 82 | Guthrie County | 31.7 | Relatively Low |
| 83 | Wapello County | 31.5 | Relatively Low |
| 84 | Fremont County | 31.1 | Relatively Low |
| 85 | Henry County | 30.7 | Relatively Low |
| 86 | Grundy County | 30.3 | Relatively Low |
| 87 | Buchanan County | 29.1 | Relatively Low |
| 88 | Harrison County | 29.1 | Relatively Low |
| 89 | Mills County | 28.6 | Relatively Low |
| 90 | Howard County | 27.2 | Relatively Low |
| 91 | Monroe County | 26.8 | Relatively Low |
| 92 | Marion County | 25.4 | Relatively Low |
| 93 | Cedar County | 25.2 | Relatively Low |
| 94 | Iowa County | 24.7 | Relatively Low |
| 95 | Jefferson County | 24.4 | Relatively Low |
| 96 | Keokuk County | 24.1 | Relatively Low |
| 97 | Benton County | 21.4 | Very Low |
| 98 | Louisa County | 20.3 | Very Low |
| 99 | Van Buren County | 19.5 | 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.
Cold Wave risk nationally:
Other hazard risks in Iowa:
Frequently asked questions
What is the highest cold wave risk county in Iowa?
Polk County, IA has the highest cold wave risk in Iowa, with a FEMA National Risk Index score of 91.3 out of 100 (rated "Relatively High").
What causes cold wave risk in Iowa?
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.