Delaware earthquake risk
New Castle County has the highest earthquake risk in Delaware, scoring 92.9 out of 100 — rated "Relatively Moderate" by FEMA's National Risk Index.
| # | County | NRI score | Rating |
|---|---|---|---|
| 1 | New Castle County | 92.9 | Relatively Moderate |
| 2 | Sussex County | 81.5 | Relatively Low |
| 3 | Kent County | 80.7 | Relatively 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.
Earthquake risk nationally:
Other hazard risks in Delaware:
Frequently asked questions
What is the highest earthquake risk county in Delaware?
New Castle County, DE has the highest earthquake risk in Delaware, with a FEMA National Risk Index score of 92.9 out of 100 (rated "Relatively Moderate").
What causes earthquake risk in Delaware?
Earthquake risk reflects expected annual losses from ground shaking. High scores concentrate in California, the Pacific Northwest, Alaska, and the New Madrid Seismic Zone (spanning Missouri, Arkansas, Tennessee, and neighboring states). NOAA's Storm Events Database does not track earthquakes, so recorded event counts are not shown.