Delaware coastal flooding risk
Sussex County has the highest coastal flooding risk in Delaware, scoring 97.6 out of 100 — rated "Very High" by FEMA's National Risk Index.
| # | County | NRI score | Rating |
|---|---|---|---|
| 1 | Sussex County | 97.6 | Very High |
| 2 | New Castle County | 83.8 | Relatively High |
| 3 | Kent County | 69.6 | Relatively Moderate |
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 Delaware:
Frequently asked questions
What is the highest coastal flooding risk county in Delaware?
Sussex County, DE has the highest coastal flooding risk in Delaware, with a FEMA National Risk Index score of 97.6 out of 100 (rated "Very High").
How many counties in Delaware are rated Very High for coastal flooding risk?
1 of 3 scored Delaware counties are rated "Very High" for coastal flooding risk by FEMA's National Risk Index.
What causes coastal flooding risk in Delaware?
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.