Massachusetts coastal flooding risk
Essex County has the highest coastal flooding risk in Massachusetts, scoring 97.8 out of 100 — rated "Very High" by FEMA's National Risk Index.
| # | County | NRI score | Rating |
|---|---|---|---|
| 1 | Essex County | 97.8 | Very High |
| 2 | Barnstable County | 94.6 | Very High |
| 3 | Plymouth County | 94.4 | Very High |
| 4 | Suffolk County | 92.2 | Relatively High |
| 5 | Norfolk County | 85.2 | Relatively High |
| 6 | Nantucket County | 70 | Relatively Moderate |
| 7 | Bristol County | 66.4 | Relatively Moderate |
| 8 | Middlesex County | 56.2 | Relatively Low |
| 9 | Dukes County | 55.4 | 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.
Coastal Flooding risk nationally:
Other hazard risks in Massachusetts:
Frequently asked questions
What is the highest coastal flooding risk county in Massachusetts?
Essex County, MA has the highest coastal flooding risk in Massachusetts, with a FEMA National Risk Index score of 97.8 out of 100 (rated "Very High").
How many counties in Massachusetts are rated Very High for coastal flooding risk?
3 of 9 scored Massachusetts counties are rated "Very High" for coastal flooding risk by FEMA's National Risk Index.
What causes coastal flooding risk in Massachusetts?
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.