Ohio coastal flooding risk
Ottawa County has the highest coastal flooding risk in Ohio, scoring 49 out of 100 — rated "Relatively Low" by FEMA's National Risk Index.
| # | County | NRI score | Rating |
|---|---|---|---|
| 1 | Ottawa County | 49 | Relatively Low |
| 2 | Erie County | 47 | Relatively Low |
| 3 | Lucas County | 42.8 | Very Low |
| 4 | Lake County | 38.6 | Very Low |
| 5 | Cuyahoga County | 33 | Very Low |
| 6 | Sandusky County | 32 | Very Low |
| 7 | Lorain County | 31.8 | Very Low |
| 8 | Ashtabula County | 28.8 | Very Low |
| 9 | Wood County | 13 | Very Low |
| 10 | Geauga County | 0 | No Rating |
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.
Coastal Flooding risk nationally:
Other hazard risks in Ohio:
Frequently asked questions
What is the highest coastal flooding risk county in Ohio?
Ottawa County, OH has the highest coastal flooding risk in Ohio, with a FEMA National Risk Index score of 49 out of 100 (rated "Relatively Low").
What causes coastal flooding risk in Ohio?
Coastal flooding scores cover storm surge, wave action, and tidal flooding along the Gulf, Atlantic, and Pacific coasts, and Great Lakes shoreline. Inland flooding is scored separately. Counties with "Not Applicable" ratings have no significant coastal exposure. Coastal flood events are reported at zone level in NOAA Storm Events and are not included in county-level counts.