Connecticut earthquake risk
Capitol Planning Region has the highest earthquake risk in Connecticut, scoring 93.5 out of 100 — rated "Relatively Moderate" by FEMA's National Risk Index.
| # | County | NRI score | Rating |
|---|---|---|---|
| 1 | Capitol Planning Region | 93.5 | Relatively Moderate |
| 2 | Western Connecticut Planning Region | 92 | Relatively Moderate |
| 3 | South Central Connecticut Planning Region | 91.5 | Relatively Moderate |
| 4 | Greater Bridgeport Planning Region | 86.4 | Relatively Low |
| 5 | Naugatuck Valley Planning Region | 86.1 | Relatively Low |
| 6 | Southeastern Connecticut Planning Region | 80.9 | Relatively Low |
| 7 | Lower Connecticut River Valley Planning Region | 74.8 | Relatively Low |
| 8 | Northwest Hills Planning Region | 66.3 | Relatively Low |
| 9 | Northeastern Connecticut Planning Region | 61.4 | 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 Connecticut:
Frequently asked questions
What is the highest earthquake risk county in Connecticut?
Capitol Planning Region, CT has the highest earthquake risk in Connecticut, with a FEMA National Risk Index score of 93.5 out of 100 (rated "Relatively Moderate").
What causes earthquake risk in Connecticut?
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.