Hillsborough County, New Hampshire
Natural disaster risk, federal disaster history and flood insurance facts.
Hillsborough County, New Hampshire has a moderate overall risk from natural hazards in FEMA's National Risk Index. Its risk score is higher than 90% of US counties. It ranks 1st of 10 counties in New Hampshire. The costliest hazards here are inland flooding, hurricanes and tornadoes. FEMA estimates about $120 million a year in expected losses, or roughly $284 per resident. Since 1973 it has been included in 29 federal disaster or emergency declarations for natural events (18 major disasters). The most recent was in March 2015 (severe winter storm and snowstorm). Fewer than 1 in 100 homes here carry federal flood insurance (751 policies). Since 1978, federal flood insurance has paid about $10 million on 629 claims here, including $5.0 million for floods in 2006.
FEMA National Risk Index December 2025; OpenFEMA declarations to Nov 6, 2026; NFIP records. Updated November 6, 2026.
Top risks in Hillsborough County
- Check the FEMA flood map for your address, and ask the seller or landlord about past flooding.
- Price a flood policy now. Most new federal policies take 30 days to start.
- Know your evacuation zone and route before June 1.
- Ask about roof age, shutters and the separate wind or hurricane deductible on your home policy.
- Pick a shelter spot: a basement, or an inside room on the lowest floor with no windows.
- Turn on emergency alerts on your phone and keep a weather radio.
All 18 hazards
What the ratings mean ›| Hazard | Rating | Score | Expected loss a year | |
|---|---|---|---|---|
| Inland flooding | 92.6 | $76M | ||
| Hurricane | 92.6 | $18M | ||
| Tornado | 82.6 | $7M | ||
| Earthquake | 88.2 | $6M | ||
| Cold wave | 66.2 | $3M | ||
| Ice storm | 95.4 | $3M | ||
| Strong wind | 86.9 | $3M | ||
| Lightning | 93.2 | $2M | ||
| Heat wave | 75.4 | $2M | ||
| Winter weather | 87.4 | $486K | ||
| Hail | 55.4 | $473K | ||
| Drought | 57.9 | $357K | ||
| Wildfire | 67.0 | $204K | ||
| Landslide | 84.2 | $39K | ||
| Avalanche | 15.2 | $28 |
Scores are percentiles: a score of 90 means higher risk than about 90% of US counties for that hazard. Hazards FEMA does not rate here are left out. Social vulnerability is very low and community resilience is relatively high in FEMA's measures.
Federal disaster history
Recent disasters nationwide ›Declarations by decade
Federal declarations for natural events that included Hillsborough County. 2020s bar runs to November 2026.
By type
Most recent
Show all 29
New Hampshire also had 1 statewide declarations that did not name single counties.
Storm history since 1955
Tornado risk by county ›The National Weather Service has logged 535 storm reports in Hillsborough County since 1955, with 1 death and 20 injuries and about $11.1 million in reported damage. The strongest on record here was an F3 tornado on August 20, 1968.
Strongest tornadoes
| Date | Strength | Near | Hurt / killed |
|---|---|---|---|
| Aug 20, 1968 | F3 | – | 1 / 0 |
| Jun 9, 1963 | F2 | – | 0 / 0 |
| Jul 3, 1997 | F2 | Greenfield | 0 / 0 |
| May 31, 1998 | F2 | Antrim | 0 / 0 |
| Jul 17, 1968 | F2 | – | 0 / 0 |
Most damaging storms
| Date | Type | Near | Damage |
|---|---|---|---|
| May 13, 2006 | Flood | Countywide | $2M |
| Apr 16, 2007 | Flood | Peterborough | $2M |
| Jul 18, 2021 | Flash Flood | West Peterborough | $1M |
| Jul 16, 2024 | Thunderstorm Wind | South Milford | $1M |
| Sep 6, 2008 | Flash Flood | Grasmere | $750K |
| Aug 22, 2009 | Flash Flood | North Vlg | $640K |
Source: NOAA Storm Events Database, county-based reports through Jul 28, 2026. Tornado records start in 1950, hail and wind in 1955, and floods and other storm types in 1996, so older decades undercount. Damage is in dollars of the year it happened and is often an estimate. Winter storms, heat and hurricanes are logged by forecast zone, not county, so they are not counted here.
Hurricanes and tropical storms
Hurricane risk by county ›Since 1851, 4 hurricanes and 20 tropical storms have passed within 65 miles of the center of Hillsborough County, 10 of them since 1950. The strongest was an unnamed hurricane in 1869, with top winds near 105 mph about 58 miles away.
Strongest storms nearby
| Date | Storm | Strength | Closest |
|---|---|---|---|
| Sep 8, 1869 | Unnamed | Category 2, 105 mph | 58 mi |
| Sep 27, 1985 | Gloria | Category 1, 80 mph | 42 mi |
| Sep 12, 1960 | Donna | Category 1, 80 mph | 60 mi |
| Sep 16, 1858 | Unnamed | Category 1, 75 mph | 57 mi |
| Jul 13, 1996 | Bertha | Tropical storm, 70 mph | 57 mi |
| Aug 24, 1893 | Unnamed | Tropical storm, 70 mph | 65 mi |
Most recent storms
| Date | Storm | Strength | Closest |
|---|---|---|---|
| Aug 28, 2011 | Irene | Tropical storm, 55 mph | 62 mi |
| Sep 17, 1999 | Floyd | Tropical storm, 60 mph | 59 mi |
| Jul 13, 1996 | Bertha | Tropical storm, 70 mph | 57 mi |
| Sep 27, 1985 | Gloria | Category 1, 80 mph | 42 mi |
| Aug 10, 1976 | Belle | Tropical storm, 45 mph | 57 mi |
| Aug 28, 1971 | Doria | Tropical storm, 55 mph | 59 mi |
Source: NOAA National Hurricane Center best-track records (HURDAT2), 1851 to 2025 for the Atlantic and 1949 to 2025 for the eastern Pacific. A storm counts if its track passed within 65 miles of the county's center while it was a tropical storm or hurricane. Strength is the storm's top sustained wind at that point, not the wind measured in the county. Older storms over the open sea were sometimes missed.
Flood insurance in Hillsborough County
Check your address flood zone ›National Flood Insurance Program (NFIP) records only; private flood policies are not included. Home counts as of Aug 3, 2026. Since 2021 NFIP prices each home separately under Risk Rating 2.0, so your price depends on the building, not the county. Ask an agent for a quote.
Homes in Hillsborough County
Older homes and mobile homes usually suffer more damage in storms, floods and earthquakes, and can cost more to insure. If you are buying, ask about roof age, foundation bolting and any retrofits. Source: US Census Bureau, American Community Survey 2020 to 2024 5-year estimates; 177,734 housing units.
Compare in New Hampshire
All 10 ›| Largest counties | Overall risk | Top hazard |
|---|---|---|
| Hillsborough County | Inland flooding | |
| Rockingham County | Inland flooding | |
| Merrimack County | Inland flooding | |
| Strafford County | Inland flooding | |
| Grafton County | Inland flooding | |
| Cheshire County | Inland flooding | |
| Belknap County | Inland flooding | |
| Carroll County | Inland flooding |
Neighboring counties
| County | Overall risk | Declarations |
|---|---|---|
| Middlesex County, MA | 31 | |
| Worcester County, MA | 30 | |
| Essex County, MA | 36 | |
| Rockingham County | 33 | |
| Merrimack County | 27 | |
| Cheshire County | 31 | |
| Sullivan County | 31 |
Cities in Hillsborough County
Common questions about Hillsborough County
What is the biggest natural hazard in Hillsborough County?
Inland flooding has the highest expected yearly losses in Hillsborough County, about $76.4 million a year in FEMA's estimate. Hurricane is second at $18.4 million.
How many federal disasters has Hillsborough County had?
Hillsborough County has been included in 29 federal disaster or emergency declarations for natural events since 1973, including 18 major disasters. The most recent was Severe Winter Storm and Snowstorm in March 2015.
Is Hillsborough County a high-risk place to live?
Its overall rating is Relatively Moderate, 1st highest of 10 in New Hampshire. A county rating covers the whole area. Risk at one address can be much higher or lower, so check the FEMA flood map and ask about the home's history.
Do I need flood insurance in Hillsborough County?
Standard home insurance does not cover flooding. About 1 in 143 homes in Hillsborough County has federal flood insurance. Lenders require it in mapped high-risk zones, but many flood claims come from outside those zones.
How many tornadoes has Hillsborough County had?
NOAA records list 19 tornadoes in Hillsborough County since 1950. The strongest was an F3 tornado on August 20, 1968. The weather service has also logged 114 hail reports and 83 floods here.
How many hurricanes have hit Hillsborough County?
NOAA's hurricane records show 4 hurricanes and 20 tropical storms passing within 65 miles of the center of Hillsborough County. The strongest was an unnamed hurricane in 1869, with winds near 105 mph.
Sources: FEMA National Risk Index (December 2025), OpenFEMA Disaster Declarations Summaries, and NFIP policy and claims data. Hazard Compass is independent and not affiliated with FEMA. These figures describe the whole county, not a single property, and are not insurance or safety advice. Report a problem.