New Hampshire Natural Disaster Risk by County
Of New Hampshire's 10 counties, 0 have a Very High natural-hazard risk rating in FEMA's National Risk Index (v1.20, December 2025); the highest is Hillsborough County (score 89.8 of 100), and expected losses across the state total $463 million a year.
OpenFEMA lists 62 federal disaster, emergency and fire management declarations for New Hampshire since 1953 (not counting COVID-19); the latest is DR-4947-NH, Severe Storm and Flooding, declared 7 October 2026.
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Most exposed counties, hazard by hazard
Top 10 by FEMA hazard risk scoreHurricane 10 rated
| # | County | Rating | Loss a year |
|---|---|---|---|
| 1 | Hillsborough County | Relatively Moderate | $18 million |
| 2 | Carroll County | Relatively Moderate | $4.8 million |
| 3 | Merrimack County | Relatively Moderate | $4.5 million |
| 4 | Rockingham County | Relatively Moderate | $5.0 million |
| 5 | Grafton County | Relatively Low | $1.7 million |
| 6 | Belknap County | Relatively Low | $1.9 million |
| 7 | Coos County | Relatively Low | $1.1 million |
| 8 | Strafford County | Relatively Low | $1.5 million |
| 9 | Cheshire County | Relatively Low | $1.5 million |
| 10 | Sullivan County | Relatively Low | $561,307 |
Tornado 10 rated
| # | County | Rating | Loss a year |
|---|---|---|---|
| 1 | Hillsborough County | Relatively Moderate | $6.5 million |
| 2 | Rockingham County | Relatively Moderate | $4.4 million |
| 3 | Merrimack County | Relatively Low | $1.9 million |
| 4 | Cheshire County | Relatively Low | $1.3 million |
| 5 | Strafford County | Relatively Low | $1.2 million |
| 6 | Belknap County | Relatively Low | $674,557 |
| 7 | Grafton County | Very Low | $378,430 |
| 8 | Sullivan County | Very Low | $382,674 |
| 9 | Carroll County | Very Low | $226,806 |
| 10 | Coos County | Very Low | $63,121 |
Inland flooding 10 rated
| # | County | Rating | Loss a year |
|---|---|---|---|
| 1 | Hillsborough County | Relatively Moderate | $76 million |
| 2 | Grafton County | Relatively Moderate | $43 million |
| 3 | Rockingham County | Relatively Moderate | $54 million |
| 4 | Merrimack County | Relatively Moderate | $34 million |
| 5 | Carroll County | Relatively Moderate | $23 million |
| 6 | Coos County | Relatively Moderate | $15 million |
| 7 | Strafford County | Relatively Moderate | $21 million |
| 8 | Cheshire County | Relatively Moderate | $20 million |
| 9 | Belknap County | Relatively Low | $16 million |
| 10 | Sullivan County | Relatively Low | $12 million |
Coastal flooding 2 rated
| # | County | Rating | Loss a year |
|---|---|---|---|
| 1 | Rockingham County | Relatively High | $12 million |
| 2 | Strafford County | Relatively Low | $57,270 |
Wildfire 10 rated
| # | County | Rating | Loss a year |
|---|---|---|---|
| 1 | Hillsborough County | Relatively Low | $203,767 |
| 2 | Rockingham County | Very Low | $63,922 |
| 3 | Merrimack County | Very Low | $24,357 |
| 4 | Strafford County | Very Low | $22,891 |
| 5 | Carroll County | Very Low | $18,825 |
| 6 | Grafton County | Very Low | $16,408 |
| 7 | Belknap County | Very Low | $13,329 |
| 8 | Cheshire County | Very Low | $12,935 |
| 9 | Coos County | Very Low | $4,936 |
| 10 | Sullivan County | Very Low | $5,835 |
Earthquake 10 rated
| # | County | Rating | Loss a year |
|---|---|---|---|
| 1 | Hillsborough County | Relatively Low | $5.8 million |
| 2 | Rockingham County | Relatively Low | $5.5 million |
| 3 | Strafford County | Relatively Low | $1.6 million |
| 4 | Merrimack County | Relatively Low | $1.5 million |
| 5 | Grafton County | Relatively Low | $847,502 |
| 6 | Carroll County | Relatively Low | $559,916 |
| 7 | Belknap County | Relatively Low | $549,505 |
| 8 | Cheshire County | Very Low | $521,910 |
| 9 | Coos County | Very Low | $221,775 |
| 10 | Sullivan County | Very Low | $235,178 |
Every New Hampshire county, highest overall risk first
10| # | County | Overall risk | Score | Loss a year | Top hazard | Declarations | Tornadoes |
|---|---|---|---|---|---|---|---|
| 1 | Hillsborough County | Relatively Moderate | 89.8 | $120 million | Ice storm | 29 | 20 |
| 2 | Rockingham County | Relatively Moderate | 85.8 | $90 million | Coastal flooding | 33 | 11 |
| 3 | Grafton County | Relatively Moderate | 81.8 | $50 million | Landslide | 38 | 13 |
| 4 | Merrimack County | Relatively Low | 78.2 | $49 million | Ice storm | 27 | 7 |
| 5 | Coos County | Relatively Low | 72.8 | $27 million | Avalanche | 26 | 7 |
| 6 | Carroll County | Relatively Low | 71.0 | $31 million | Winter weather | 34 | 8 |
| 7 | Strafford County | Relatively Low | 64.1 | $29 million | Ice storm | 23 | 6 |
| 8 | Cheshire County | Relatively Low | 60.5 | $27 million | Landslide | 31 | 18 |
| 9 | Belknap County | Relatively Low | 57.4 | $24 million | Lightning | 28 | 12 |
| 10 | Sullivan County | Very Low | 37.6 | $15 million | Landslide | 31 | 6 |
Score: FEMA's national percentile (higher = more risk). Declarations: federal declarations that named the county since 1953, not counting COVID-19. Tornadoes: NOAA SPC tornadoes that touched the county, 1950–2025.
Latest federal declarations in New Hampshire
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What this page shows, and what it misses
FEMA's National Risk Index compares every US county with every other for 18 natural hazards, combining expected losses with social vulnerability and community resilience. It is a planning-level estimate for nationwide comparison, not a flood-zone map and not the risk to any one property — for flood zones use FEMA's Flood Map Service Center ↗. Federal declarations exclude state declarations and SBA or USDA designations.
Federal Emergency Management Agency (FEMA), National Risk Index Dataset: National Risk Index Counties - v1.20.0 (December 2025). Retrieved from https://services.arcgis.com/XG15cJAlne2vxtgt/ArcGIS/rest/services/National_Risk_Index_Counties/FeatureServer/0/query on November 2, 2026, 1:20 PM EST. This product uses the Federal Emergency Management Agency’s National Risk Index dataset API or downloadable datasets but is not endorsed by FEMA. The Federal Government or FEMA cannot vouch for the data or analyses derived from these data after the data have been retrieved from the Agency's website(s).
Federal Emergency Management Agency (FEMA), OpenFEMA Dataset: Disaster Declarations Summaries - v2, retrieved from https://www.fema.gov/api/open/v2/DisasterDeclarationsSummaries on November 2, 2026, 1:21 PM EST. This product uses the Federal Emergency Management Agency's OpenFEMA API, but is not endorsed by FEMA. The Federal Government or FEMA cannot vouch for the data or analyses derived from these data after the data have been retrieved from the Agency's website(s).
Tornado records: NOAA/NWS Storm Prediction Center, Severe Weather Database, tornadoes 1950–2025 (https://www.spc.noaa.gov/wcm/data/1950-2025_actual_tornadoes.csv, downloaded 2 November 2026). Public domain; not endorsed by NOAA. Compiled by Global Incident Tracker.
Questions about New Hampshire
Which county in New Hampshire has the highest natural disaster risk?
Of New Hampshire's 10 counties, 0 have a Very High natural-hazard risk rating in FEMA's National Risk Index (v1.20, December 2025); the highest is Hillsborough County (score 89.8 of 100), and expected losses across the state total $463 million a year.
Which New Hampshire counties are most at risk from tornadoes?
By FEMA's National Risk Index tornado risk score: Hillsborough County, Rockingham County, Merrimack County. These are planning-level estimates for whole counties, not maps of individual properties.
Which New Hampshire counties are most at risk from hurricanes?
By FEMA's National Risk Index hurricane risk score: Hillsborough County, Carroll County, Merrimack County. These are planning-level estimates for whole counties, not maps of individual properties.
How many FEMA disaster declarations has New Hampshire had?
OpenFEMA lists 62 federal disaster, emergency and fire management declarations for New Hampshire since 1953 (not counting COVID-19); the latest is DR-4947-NH, Severe Storm and Flooding, declared 7 October 2026.