Natural disaster risk in Iowa, by county
All 99 counties in Iowa, ranked by FEMA's National Risk Index composite risk score, with each one's highest-rated hazard. Other states
At a glance
0
Very high risk
0
Relatively high risk
5
Relatively moderate risk
30
Relatively low risk
64
Very low risk
Highest overall risk: Polk County (relatively moderate, score 92.0). Lowest: Worth County (very low, score 9.9).
Top hazards in Iowa
| Hazard | Counties rated relatively high or very high | Average score |
|---|---|---|
| Drought | 45 of 99 | 86.2 |
| Strong wind | 14 of 99 | 56.9 |
| Hail | 9 of 99 | 73.7 |
| Winter weather | 9 of 99 | 50.8 |
| Tornado | 8 of 99 | 61.0 |
All counties, highest risk first
| # | County | Overall risk | Highest-rated hazard |
|---|---|---|---|
| 1 | Polk County | Relatively moderate 92 | Strong wind (very high) |
| 2 | Johnson County | Relatively moderate 87.4 | Strong wind (very high) |
| 3 | Linn County | Relatively moderate 86.7 | Strong wind (very high) |
| 4 | Scott County | Relatively moderate 84.9 | Hail (relatively high) |
| 5 | Woodbury County | Relatively moderate 83.3 | Tornado (relatively high) |
| 6 | Pottawattamie County | Relatively low 80.4 | Hail (relatively high) |
| 7 | Black Hawk County | Relatively low 76.6 | Drought (relatively high) |
| 8 | Cerro Gordo County | Relatively low 69.6 | Drought (relatively high) |
| 9 | Story County | Relatively low 68.8 | Drought (relatively high) |
| 10 | Wapello County | Relatively low 65.3 | Drought (relatively high) |
| 11 | Clinton County | Relatively low 64.8 | Strong wind (relatively high) |
| 12 | Dubuque County | Relatively low 63.6 | Hail (relatively moderate) |
| 13 | Lee County | Relatively low 62.9 | Hail (relatively moderate) |
| 14 | Marshall County | Relatively low 62.5 | Drought (relatively high) |
| 15 | Crawford County | Relatively low 60.8 | Drought (relatively high) |
| 16 | Dallas County | Relatively low 60.6 | Drought (relatively high) |
| 17 | Cass County | Relatively low 60.1 | Drought (relatively high) |
| 18 | Webster County | Relatively low 60 | Drought (relatively high) |
| 19 | Hardin County | Relatively low 58.4 | Hail (relatively high) |
| 20 | Muscatine County | Relatively low 57.8 | Strong wind (relatively high) |
| 21 | Carroll County | Relatively low 57.6 | Hail (relatively high) |
| 22 | Des Moines County | Relatively low 55.8 | Strong wind (relatively high) |
| 23 | Sioux County | Relatively low 52.4 | Hail (relatively high) |
| 24 | Fayette County | Relatively low 50.9 | Drought (relatively moderate) |
| 25 | Davis County | Relatively low 50.3 | Drought (relatively high) |
| 26 | Delaware County | Relatively low 49.7 | Hail (relatively moderate) |
| 27 | Adair County | Relatively low 49.5 | Drought (relatively high) |
| 28 | Union County | Relatively low 49.5 | Drought (relatively high) |
| 29 | Plymouth County | Relatively low 49.2 | Hail (relatively moderate) |
| 30 | Floyd County | Relatively low 47.7 | Drought (relatively high) |
| 31 | Tama County | Relatively low 45.3 | Drought (relatively high) |
| 32 | Calhoun County | Relatively low 44.6 | Drought (relatively high) |
| 33 | Washington County | Relatively low 44.2 | Strong wind (relatively high) |
| 34 | Jasper County | Relatively low 43.7 | Drought (relatively high) |
| 35 | Hamilton County | Relatively low 42.9 | Drought (relatively high) |
| 36 | Emmet County | Very low 42.7 | Drought (relatively high) |
| 37 | Clayton County | Very low 42.2 | Landslide (relatively moderate) |
| 38 | Wright County | Very low 41.5 | Drought (relatively high) |
| 39 | Appanoose County | Very low 41.2 | Drought (relatively high) |
| 40 | Page County | Very low 40.2 | Drought (relatively moderate) |
| 41 | Buena Vista County | Very low 39.3 | Hail (relatively moderate) |
| 42 | Audubon County | Very low 38.6 | Drought (relatively high) |
| 43 | Taylor County | Very low 38.5 | Drought (relatively high) |
| 44 | Allamakee County | Very low 38.2 | Landslide (relatively moderate) |
| 45 | Mitchell County | Very low 37.7 | Strong wind (relatively high) |
| 46 | Clay County | Very low 36.4 | Hail (relatively moderate) |
| 47 | Dickinson County | Very low 36.3 | Winter weather (relatively moderate) |
| 48 | Winneshiek County | Very low 36.2 | Hail (relatively moderate) |
| 49 | Jackson County | Very low 36.1 | Landslide (relatively moderate) |
| 50 | Warren County | Very low 36.1 | Drought (relatively high) |
| 51 | Madison County | Very low 35.5 | Drought (relatively high) |
| 52 | Marion County | Very low 34.4 | Drought (relatively moderate) |
| 53 | Cherokee County | Very low 34.1 | Hail (relatively moderate) |
| 54 | Montgomery County | Very low 33.7 | Drought (relatively moderate) |
| 55 | Van Buren County | Very low 33.6 | Drought (relatively moderate) |
| 56 | Pocahontas County | Very low 33 | Drought (relatively high) |
| 57 | Jones County | Very low 32.7 | Drought (relatively moderate) |
| 58 | Kossuth County | Very low 32.3 | Drought (relatively high) |
| 59 | Greene County | Very low 31.8 | Drought (relatively high) |
| 60 | Chickasaw County | Very low 31.7 | Drought (relatively moderate) |
| 61 | Harrison County | Very low 31.3 | Drought (relatively moderate) |
| 62 | Poweshiek County | Very low 31.3 | Drought (relatively high) |
| 63 | Henry County | Very low 30.9 | Heat wave (relatively moderate) |
| 64 | Winnebago County | Very low 30.7 | Drought (relatively high) |
| 65 | Lucas County | Very low 29.7 | Drought (relatively high) |
| 66 | Mahaska County | Very low 29.7 | Drought (relatively moderate) |
| 67 | Benton County | Very low 28.8 | Drought (relatively moderate) |
| 68 | Hancock County | Very low 28.8 | Drought (relatively high) |
| 69 | Boone County | Very low 28.4 | Drought (relatively high) |
| 70 | Iowa County | Very low 28.2 | Strong wind (relatively moderate) |
| 71 | Sac County | Very low 27.3 | Drought (relatively high) |
| 72 | Butler County | Very low 27.1 | Drought (relatively moderate) |
| 73 | Jefferson County | Very low 27.1 | Drought (relatively moderate) |
| 74 | Guthrie County | Very low 26.5 | Drought (relatively high) |
| 75 | Monona County | Very low 25.1 | Drought (relatively moderate) |
| 76 | Bremer County | Very low 24.6 | Drought (relatively moderate) |
| 77 | Humboldt County | Very low 24.1 | Drought (relatively high) |
| 78 | Buchanan County | Very low 24 | Drought (relatively moderate) |
| 79 | Decatur County | Very low 23.6 | Drought (relatively high) |
| 80 | Shelby County | Very low 22.8 | Drought (relatively moderate) |
| 81 | Wayne County | Very low 22 | Drought (relatively high) |
| 82 | Franklin County | Very low 21.9 | Drought (relatively high) |
| 83 | Keokuk County | Very low 21.9 | Drought (relatively moderate) |
| 84 | Cedar County | Very low 21.5 | Drought (relatively moderate) |
| 85 | Adams County | Very low 20.4 | Drought (relatively high) |
| 86 | Lyon County | Very low 19.2 | Hail (relatively moderate) |
| 87 | Mills County | Very low 18.5 | Drought (relatively moderate) |
| 88 | Clarke County | Very low 18.4 | Drought (relatively high) |
| 89 | Ida County | Very low 18.4 | Hail (relatively moderate) |
| 90 | Louisa County | Very low 17.5 | Drought (relatively moderate) |
| 91 | O'Brien County | Very low 16.4 | Hail (relatively moderate) |
| 92 | Howard County | Very low 15.6 | Drought (relatively moderate) |
| 93 | Palo Alto County | Very low 15.5 | Drought (relatively moderate) |
| 94 | Fremont County | Very low 15 | Drought (relatively moderate) |
| 95 | Osceola County | Very low 14.9 | Hail (relatively moderate) |
| 96 | Ringgold County | Very low 14.2 | Drought (relatively high) |
| 97 | Grundy County | Very low 13.1 | Drought (relatively moderate) |
| 98 | Monroe County | Very low 10.3 | Drought (relatively moderate) |
| 99 | Worth County | Very low 9.9 | Drought (relatively moderate) |
How to read these ratings
- Ratings run in five steps: very low, relatively low, relatively moderate, relatively high and very high. They compare a county with every other US county; they are not a measure of danger on their own.
- Scores run from 0 to 100 and are national percentiles. The bar shows the score: a score of 80 means a higher value than 80% of US counties.
- Overall risk combines the expected annual loss with social vulnerability and community resilience.
- Expected annual loss is the average yearly loss to buildings, people and agriculture the model expects from all 18 hazards.
- Social vulnerability describes how hard it may be for people to prepare for and recover from a disaster. Higher is worse.
- Community resilience describes a community's ability to prepare, adapt and recover. Higher is better.
- "Not applicable" means FEMA does not model that hazard there (for example, hurricanes far inland).
About this data
Source: FEMA National Risk Index, version 1.20, released December 2025, published by the Federal Emergency Management Agency (US public domain). About the National Risk Index. The index is a model of relative risk built from historical hazard records, what is exposed and community factors. It is not a forecast, it does not describe any single property, and it is not insurance or financial advice. For decisions about a specific address, check FEMA's flood maps and your local emergency management office.
Questions
Which county in Iowa has the highest natural disaster risk?
Polk County has the highest composite risk score in Iowa in FEMA's National Risk Index: 92.0, rated relatively moderate.
Which county in Iowa has the lowest natural disaster risk?
Worth County has the lowest composite risk score in Iowa: 9.9, rated very low. A low score means lower modelled risk compared with other US counties, not no risk.
What natural disasters is Iowa most at risk from?
Across Iowa, the hazards rated highest in the most counties are drought, strong wind, hail, according to FEMA's National Risk Index. Each county page lists all 18 hazards.
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