New Hampshire lightning risk
Belknap County has the highest lightning risk in New Hampshire, scoring 94.8 out of 100 — rated "Relatively High" by FEMA's National Risk Index.
| # | County | NRI score | Rating |
NOAA events 2016–2026 |
|---|---|---|---|---|
| 1 | Belknap County | 94.8 | Relatively High | 1 |
| 2 | Hillsborough County | 93.2 | Relatively High | 0 |
| 3 | Merrimack County | 89.2 | Relatively High | 2 |
| 4 | Grafton County | 80.9 | Relatively Moderate | 0 |
| 5 | Cheshire County | 78.6 | Relatively Moderate | 0 |
| 6 | Rockingham County | 74.8 | Relatively Moderate | 0 |
| 7 | Strafford County | 74.3 | Relatively Moderate | 0 |
| 8 | Carroll County | 67 | Relatively Moderate | 1 |
| 9 | Coos County | 52.4 | Relatively Low | 1 |
| 10 | Sullivan County | 52.4 | Relatively Low | 0 |
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.
Lightning risk nationally:
Other hazard risks in New Hampshire:
Frequently asked questions
What is the highest lightning risk county in New Hampshire?
Belknap County, NH has the highest lightning risk in New Hampshire, with a FEMA National Risk Index score of 94.8 out of 100 (rated "Relatively High").
What causes lightning risk in New Hampshire?
Lightning risk reflects expected annual losses from cloud-to-ground strikes, which ignite building fires, damage electrical systems, and cause fatalities. Florida consistently leads the US in lightning density. High scores also appear across the Gulf Coast, Southeast, and central Plains, where afternoon convective storms are most frequent in summer months.