Which county in Ohio has the lowest flood risk?

Greene has the lowest flood risk in Ohio, at 33.9.

What is the flood risk in Greene?

Greene is ranked #1 in Ohio for flood risk, at 33.9.

What are the top counties in Ohio for flood risk?

Greene (33.9), then Mahoning (34.9), and Hamilton (36.9). The full top 25 is in the table on this page.

How is this flood risk ranking calculated?

Counties in Ohio 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 Ohio compare to the rest of the US for flood risk?

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

Lowest Flood Risk Counties in Ohio (2026)

Lowest counties for flood risk in Ohio

Top 25 of 88 counties with data.

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

Lowest counties for flood risk in Ohio

Rank	County	Value
01	Greene33.9 County page
02	Mahoning34.9 County page
03	Hamilton36.9 County page
04	Medina37.1 County page
05	Clermont38.0 County page
06	Cuyahoga38.7 County page
07	Wayne38.9 County page
08	Richland40.3 County page
09	Summit41.0 County page
10	Montgomery41.2 County page
11	Portage42.0 County page
12	Madison42.4 County page
13	Van Wert43.2 County page
14	Clark43.2 County page
15	Stark43.8 County page
16	Lucas45.7 County page
17	Marion46.1 County page
18	Crawford47.3 County page
19	Franklin47.3 County page
20	Fulton50.1 County page
21	Harrison50.5 County page
22	Allen50.6 County page
23	Lorain50.7 County page
24	Trumbull51.1 County page
25	Clinton52.5 County page

How this ranking works

This page ranks Ohio 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 Ohio has the lowest flood risk?: Greene has the lowest flood risk in Ohio, at 33.9.
What is the flood risk in Greene?: Greene is ranked #1 in Ohio for flood risk, at 33.9.
What are the top counties in Ohio for flood risk?: Greene (33.9), then Mahoning (34.9), and Hamilton (36.9). The full top 25 is in the table on this page.
How is this flood risk ranking calculated?: Counties in Ohio 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 Ohio compare to the rest of the US for flood risk?: This list is Ohio only. See the national ranking of the lowest counties for flood risk at hearthmap.app/best/lowest-flood-risk.