riskbycounty
FEMA NRI v1.20Released December 2025Methodology

Iowa Disaster Risk

Natural disaster risk data for all 99 counties.

FEMA release

December 2025

Mean county NRI score

39.7

Counties with Data

99

of 99 total

County risk atlas

Iowa hazard exposure by county

FEMA NRI v1.20 scores on a 0–100 relative scale. Toggle the composite and five selected hazard categories out of FEMA's 18. Flood is the higher of Coastal Flooding and Inland Flooding NRI scores.

Counties

99/99

Mean county NRI score

39.7

Risk layers

6

All Iowa Counties

CountyNRI score
Polk County92.0
Johnson County87.4
Linn County86.7
Scott County84.9
Woodbury County83.3
Pottawattamie County80.4
Black Hawk County76.6
Cerro Gordo County69.6
Story County68.8
Wapello County65.3
Clinton County64.8
Dubuque County63.6
Lee County62.9
Marshall County62.5
Crawford County60.8
Dallas County60.6
Cass County60.1
Webster County60.0
Hardin County58.4
Muscatine County57.8
Carroll County57.6
Des Moines County55.8
Sioux County52.4
Fayette County50.9
Davis County50.3
Delaware County49.7
Union County49.5
Adair County49.5
Plymouth County49.2
Floyd County47.7
Tama County45.3
Calhoun County44.6
Washington County44.2
Jasper County43.7
Hamilton County42.9
Emmet County42.7
Clayton County42.2
Wright County41.5
Appanoose County41.2
Page County40.2
Buena Vista County39.3
Audubon County38.6
Taylor County38.5
Allamakee County38.2
Mitchell County37.7
Clay County36.4
Dickinson County36.3
Winneshiek County36.2
Warren County36.1
Jackson County36.1
Madison County35.5
Marion County34.4
Cherokee County34.1
Montgomery County33.7
Van Buren County33.6
Pocahontas County33.0
Jones County32.7
Kossuth County32.3
Greene County31.8
Chickasaw County31.7
Harrison County31.3
Poweshiek County31.3
Henry County30.9
Winnebago County30.7
Mahaska County29.7
Lucas County29.7
Benton County28.8
Hancock County28.8
Boone County28.4
Iowa County28.2
Sac County27.3
Butler County27.1
Jefferson County27.1
Guthrie County26.5
Monona County25.1
Bremer County24.6
Humboldt County24.1
Buchanan County24.0
Decatur County23.6
Shelby County22.8
Wayne County22.0
Franklin County21.9
Keokuk County21.9
Cedar County21.5
Adams County20.4
Lyon County19.2
Mills County18.5
Clarke County18.4
Ida County18.4
Louisa County17.5
O'Brien County16.4
Howard County15.6
Palo Alto County15.5
Fremont County15.0
Osceola County14.9
Ringgold County14.2
Grundy County13.1
Monroe County10.3
Worth County9.9

Frequently Asked Questions

How many Iowa county records are included?
RiskByCounty includes 99 Iowa county records from FEMA NRI v1.20 (December 2025).
Which FEMA county ratings appear in Iowa?
FEMA NRI v1.20 (December 2025) county rating counts for Iowa: Very Low: 64; Relatively Low: 30; Relatively Moderate: 5; Relatively High: 0; Very High: 0; Not available: 0.
How complete are the five selected hazard fields for Iowa?
FEMA NRI v1.20 (December 2025) availability among 99 county records: Flood: 99 of 99; Wildfire: 99 of 99; Tornado: 99 of 99; Earthquake: 99 of 99; Hurricane: 82 of 99. RiskByCounty displays five selected hazard categories out of FEMA's 18.

Official Ready.gov resource

Continue to Ready.gov for federal emergency-planning information maintained outside RiskByCounty.

Visit Ready.gov →

Data Source

County data sourced from FEMA National Risk Index v1.20, released December 2025. Values are labeled NRI score (0–100 relative scale). RiskByCounty displays five selected hazard categories out of FEMA's 18; flood is the higher of the Coastal Flooding and Inland Flooding source scores.

RiskByCounty presents county-level source fields and deterministic arithmetic summaries.

← Back to All States

Explore more data for Iowa

Property TaxCost of LivingCrime RateIncomeHealthSchoolsWater QualityWeatherCounty Score