Which county in Iowa has the lowest flood risk?

Warren has the lowest flood risk in Iowa, at 30.7.

What is the flood risk in Warren?

Warren is ranked #1 in Iowa for flood risk, at 30.7.

What are the top counties in Iowa for flood risk?

Warren (30.7), then Greene (33.4), and Ringgold (35.5). The full top 25 is in the table on this page.

How is this flood risk ranking calculated?

Counties in Iowa are ranked by flood risk (FEMA National Risk Index, FEMA NRI v1.20), lowest first. Values describe the county, not an individual property. Source vintage is shown on the page.

How does Iowa compare to the rest of the US for flood risk?

This list is Iowa only. See the national ranking of the lowest counties for flood risk at hearthmap.app/best/lowest-flood-risk.

Lowest Flood Risk Counties in Iowa (2026)

Lowest counties for flood risk in Iowa

Top 25 of 99 counties with data.

Ranked by flood risk (FEMA National Risk Index, FEMA NRI v1.20), lowest first.

Lowest counties for flood risk in Iowa

Rank	County	Value
01	Warren30.7 County page
02	Greene33.4 County page
03	Ringgold35.5 County page
04	Palo Alto36.8 County page
05	Black Hawk37.8 County page
06	Polk38.4 County page
07	Dubuque39.1 County page
08	Monroe40.5 County page
09	Webster40.9 County page
10	Story43.2 County page
11	Poweshiek43.9 County page
12	Page44.9 County page
13	Linn45.1 County page
14	Jefferson45.3 County page
15	Wayne46.2 County page
16	Buena Vista46.4 County page
17	Woodbury46.9 County page
18	Pottawattamie47.7 County page
19	Jasper47.9 County page
20	Mahaska48.1 County page
21	Marion48.3 County page
22	Grundy50.7 County page
23	Johnson51.5 County page
24	Worth51.7 County page
25	Lucas52.2 County page

How this ranking works

This page ranks Iowa counties by flood risk, sorted so the lowest places appear first. Click any county to see its housing, schools, crime, and demographics in detail.

For flood risk, a lower value is generally more favorable, so the top of the list is the lowest. Want to weigh flood risk against schools, taxes, commute, and more at once? Use the live map to build a custom match.

Data comes from public sources. Source attribution and the exact data vintage are shown above and on the full map of flood risk.

Frequently asked questions

Which county in Iowa has the lowest flood risk?: Warren has the lowest flood risk in Iowa, at 30.7.
What is the flood risk in Warren?: Warren is ranked #1 in Iowa for flood risk, at 30.7.
What are the top counties in Iowa for flood risk?: Warren (30.7), then Greene (33.4), and Ringgold (35.5). The full top 25 is in the table on this page.
How is this flood risk ranking calculated?: Counties in Iowa are ranked by flood risk (FEMA National Risk Index, FEMA NRI v1.20), lowest first. Values describe the county, not an individual property. Source vintage is shown on the page.
How does Iowa compare to the rest of the US for flood risk?: This list is Iowa only. See the national ranking of the lowest counties for flood risk at hearthmap.app/best/lowest-flood-risk.