Massachusetts earthquake risk
Middlesex County has the highest earthquake risk in Massachusetts, scoring 96.1 out of 100 — rated "Relatively Moderate" by FEMA's National Risk Index.
| # | County | NRI score | Rating |
|---|---|---|---|
| 1 | Middlesex County | 96.1 | Relatively Moderate |
| 2 | Suffolk County | 95 | Relatively Moderate |
| 3 | Essex County | 94.9 | Relatively Moderate |
| 4 | Norfolk County | 91.5 | Relatively Moderate |
| 5 | Hampden County | 90.6 | Relatively Moderate |
| 6 | Worcester County | 89.3 | Relatively Low |
| 7 | Bristol County | 88.6 | Relatively Low |
| 8 | Plymouth County | 87.7 | Relatively Low |
| 9 | Barnstable County | 78.1 | Relatively Low |
| 10 | Berkshire County | 72.1 | Relatively Low |
| 11 | Hampshire County | 70.1 | Relatively Low |
| 12 | Franklin County | 58.7 | Very Low |
| 13 | Dukes County | 33.5 | Very Low |
| 14 | Nantucket County | 22.4 | 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.
Earthquake risk nationally:
Other hazard risks in Massachusetts:
Frequently asked questions
What is the highest earthquake risk county in Massachusetts?
Middlesex County, MA has the highest earthquake risk in Massachusetts, with a FEMA National Risk Index score of 96.1 out of 100 (rated "Relatively Moderate").
What causes earthquake risk in Massachusetts?
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.