New Hampshire coastal flooding risk
Rockingham County has the highest coastal flooding risk in New Hampshire, scoring 92.8 out of 100 — rated "Relatively High" by FEMA's National Risk Index.
| # | County | NRI score | Rating |
|---|---|---|---|
| 1 | Rockingham County | 92.8 | Relatively High |
| 2 | Strafford County | 44.6 | 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 New Hampshire:
Frequently asked questions
What is the highest coastal flooding risk county in New Hampshire?
Rockingham County, NH has the highest coastal flooding risk in New Hampshire, with a FEMA National Risk Index score of 92.8 out of 100 (rated "Relatively High").
What causes coastal flooding risk in New Hampshire?
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.