Portsmouth, NH
Local storm history & FEMA National Risk Index data
Portsmouth is rated Relatively Moderate for overall natural hazard risk — near the middle compared to other US counties — based on FEMA's National Risk Index for Rockingham County, NH. The county's highest-rated hazards are coastal flooding, ice storm, and inland flooding.
Storm events near Portsmouth
NOAA-recorded tornado, hail, and flood events within 25 miles of Portsmouth's center, 2016–2026 — the only hazards NOAA reports with exact coordinates, so these counts are specific to Portsmouth itself, not the whole county.
County-wide hazard risk
Every other hazard FEMA and NOAA track — including drought — is only scored at the county level. These are Rockingham County's FEMA National Risk Index scores, covering Portsmouth along with the rest of the county, not a Portsmouth-specific figure.
| Hazard | NRI score | Rating |
|---|---|---|
| Wildfire | 47.8 | Very Low |
| Inland Flooding | 89.1 | Relatively Moderate |
| Coastal Flooding | 92.8 | Relatively High |
| Earthquake | 87.5 | Relatively Low |
| Heat Wave | 65 | Relatively Low |
| Tornado | 73.5 | Relatively Moderate |
| Avalanche | 4.4 | Very Low |
| Cold Wave | 57.4 | Relatively Low |
| Drought | 77.1 | Relatively Moderate |
| Hail | 35.5 | Relatively Low |
| Hurricane | 83.8 | Relatively Moderate |
| Ice Storm | 91.3 | Relatively High |
| Landslide | 72 | Relatively Low |
| Lightning | 74.8 | Relatively Moderate |
| Strong Wind | 72.5 | Relatively Moderate |
| Tsunami | — | Insufficient Data |
| Volcanic Activity | — | Not Applicable |
| Winter Weather | 65.6 | Relatively Moderate |
Source: FEMA National Risk Index v1.20.0, December 2025. See the methodology page for definitions, or the full Rockingham County risk profile for disaster declarations, social vulnerability, and climate projection data.
More on Rockingham County:
Frequently asked questions
What natural hazards is Portsmouth, NH at risk of?
Portsmouth is rated Relatively Moderate for overall natural hazard risk by FEMA's National Risk Index — near the middle compared to other US counties. The highest-rated hazards for Rockingham County, where Portsmouth is located, are coastal flooding, ice storm, and inland flooding.
What is Portsmouth's biggest natural hazard risk?
Coastal Flooding is the highest-rated hazard for Rockingham County, where Portsmouth is located, scoring 92.8 out of 100 on FEMA's National Risk Index (rated "Relatively High").
Is Portsmouth a high-risk area for natural disasters?
Somewhat — Portsmouth carries near the middle compared to other US counties for overall natural hazard risk, per FEMA's National Risk Index rating of "Relatively Moderate" for Rockingham County.
Has Portsmouth had tornadoes, hail, or flooding?
NOAA has recorded 37 hail, 17 inland flooding events within 25 miles of Portsmouth since 2016.