Wisconsin coastal flooding risk
Brown County has the highest coastal flooding risk in Wisconsin, scoring 46.4 out of 100 — rated "Relatively Low" by FEMA's National Risk Index.
| # | County | NRI score | Rating |
|---|---|---|---|
| 1 | Brown County | 46.4 | Relatively Low |
| 2 | Door County | 40.2 | Very Low |
| 3 | Oconto County | 37.8 | Very Low |
| 4 | Milwaukee County | 35.6 | Very Low |
| 5 | Manitowoc County | 32.2 | Very Low |
| 6 | Ozaukee County | 31 | Very Low |
| 7 | Kenosha County | 30.8 | Very Low |
| 8 | Kewaunee County | 30.2 | Very Low |
| 9 | Sheboygan County | 27 | Very Low |
| 10 | Racine County | 25 | Very Low |
| 11 | Bayfield County | 24.4 | Very Low |
| 12 | Douglas County | 24 | Very Low |
| 13 | Iron County | 21.8 | Very Low |
| 14 | Marinette County | 15.8 | Very Low |
| 15 | Ashland County | 14.6 | Very Low |
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 Wisconsin:
Frequently asked questions
What is the highest coastal flooding risk county in Wisconsin?
Brown County, WI has the highest coastal flooding risk in Wisconsin, with a FEMA National Risk Index score of 46.4 out of 100 (rated "Relatively Low").
What causes coastal flooding risk in Wisconsin?
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.