Home › New Hampshire › Hillsborough County

Hillsborough County, New Hampshire

Natural disaster risk, federal disaster history and flood insurance facts.

Relatively Moderate overall risk
1st of 10highest risk in New Hampshire
$120Mexpected losses a year
29federal declarations
1 in 143homes with flood insurance
Photo: Quintin Soloviev, CC BY 4.0

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

$76.4 million a yearExpected losses. Damaging events about 2 times a year.
  • 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.

Hurricane

Moderate
$18.4 million a yearExpected losses. Damaging events about once every 9 years.
  • 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.

Tornado

Moderate
$6.5 million a yearExpected losses. Damaging events about once every 6 years.
  • 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.
HazardRatingScoreExpected loss a year
Inland floodingModerate92.6
$76M
HurricaneModerate92.6
$18M
TornadoModerate82.6
$7M
EarthquakeLow88.2
$6M
Cold waveModerate66.2
$3M
Ice stormVery High95.4
$3M
Strong windHigh86.9
$3M
LightningHigh93.2
$2M
Heat waveLow75.4
$2M
Winter weatherHigh87.4
$486K
HailLow55.4
$473K
DroughtLow57.9
$357K
WildfireLow67.0
$204K
LandslideLow84.2
$39K
AvalancheVery Low15.2
$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

Severe Storm13
Snowstorm6
Flood5
Hurricane4
Severe Ice Storm1

Most recent

Mar 25, 2015Severe Winter Storm and SnowstormMajor disaster
Mar 19, 2013Severe Winter Storm and SnowstormMajor disaster
Oct 30, 2012Hurricane SandyEmergency
Dec 5, 2011Severe Storm and SnowstormMajor disaster
Nov 1, 2011Severe StormEmergency
Aug 27, 2011Hurricane IreneEmergency
May 12, 2010Severe Storms and FloodingMajor disaster
Mar 29, 2010Severe Winter StormMajor disaster
Jan 2, 2009Severe Winter StormMajor disaster
Dec 13, 2008Severe Winter StormEmergency
Show all 29
Oct 3, 2008Severe Storms and FloodingMajor disaster
Apr 27, 2007Severe Storms and FloodingMajor disaster
May 25, 2006Severe Storms and FloodingMajor disaster
Oct 26, 2005Severe Storms and FloodingMajor disaster
Sep 19, 2005Hurricane Katrina EvacuationEmergency
Apr 28, 2005Record SnowEmergency
Mar 30, 2005Record And/Or Near Record SnowEmergency
Jan 15, 2004SnowEmergency
Mar 11, 2003SnowEmergency
Mar 28, 2001SnowEmergency
Jul 2, 1998Severe Storms and FloodingMajor disaster
Jan 15, 1998Severe Ice Storm, Rains and High WindsMajor disaster
Oct 29, 1996Fall Northeaster RainstormMajor disaster
Mar 16, 1993Blizzards, High Winds & Record SnowfallEmergency
Sep 9, 1991Hurricane Bob & Severe StormsMajor disaster
Aug 29, 1990Severe Storms & FloodingMajor disaster
Apr 16, 1987Severe Storms & FloodingMajor disaster
Aug 27, 1986Severe Storms, FloodingMajor disaster
Jul 11, 1973Severe Storms & FloodingMajor disaster

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.

19tornadoes
114hail reports, largest 2 inches
292damaging thunderstorm winds
83floods and flash floods

Strongest tornadoes

DateStrengthNearHurt / killed
Aug 20, 1968F3–1 / 0
Jun 9, 1963F2–0 / 0
Jul 3, 1997F2Greenfield0 / 0
May 31, 1998F2Antrim0 / 0
Jul 17, 1968F2–0 / 0

Most damaging storms

DateTypeNearDamage
May 13, 2006FloodCountywide$2M
Apr 16, 2007FloodPeterborough$2M
Jul 18, 2021Flash FloodWest Peterborough$1M
Jul 16, 2024Thunderstorm WindSouth Milford$1M
Sep 6, 2008Flash FloodGrasmere$750K
Aug 22, 2009Flash FloodNorth 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.

4hurricanes
0major hurricanes (Category 3+)
20tropical storms
2011most recent: Irene

Strongest storms nearby

DateStormStrengthClosest
Sep 8, 1869UnnamedCategory 2, 105 mph58 mi
Sep 27, 1985GloriaCategory 1, 80 mph42 mi
Sep 12, 1960DonnaCategory 1, 80 mph60 mi
Sep 16, 1858UnnamedCategory 1, 75 mph57 mi
Jul 13, 1996BerthaTropical storm, 70 mph57 mi
Aug 24, 1893UnnamedTropical storm, 70 mph65 mi

Most recent storms

DateStormStrengthClosest
Aug 28, 2011IreneTropical storm, 55 mph62 mi
Sep 17, 1999FloydTropical storm, 60 mph59 mi
Jul 13, 1996BerthaTropical storm, 70 mph57 mi
Sep 27, 1985GloriaCategory 1, 80 mph42 mi
Aug 10, 1976BelleTropical storm, 45 mph57 mi
Aug 28, 1971DoriaTropical storm, 55 mph59 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 ›
0.7%of homes have federal flood insurance (751 policies)
34.5%of homes in mapped high-risk flood zones are insured
$10.4 millionpaid on 629 flood claims since 1978
2006costliest year, with $5 million paid

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

$421,100median home value (New Hampshire $402,500, US $332,700)
1978median year homes were built (New Hampshire 1979, US 1980)
53%of homes built before 1980, before many modern wind, quake and flood building rules
1.9%of homes are mobile homes, which are the least safe in tornadoes and high winds

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 countiesOverall riskTop hazard
Hillsborough CountyModerateInland flooding
Rockingham CountyModerateInland flooding
Merrimack CountyLowInland flooding
Strafford CountyLowInland flooding
Grafton CountyModerateInland flooding
Cheshire CountyLowInland flooding
Belknap CountyLowInland flooding
Carroll CountyLowInland flooding

Neighboring counties

CountyOverall riskDeclarations
Middlesex County, MAHigh31
Worcester County, MAModerate30
Essex County, MAHigh36
Rockingham CountyModerate33
Merrimack CountyLow27
Cheshire CountyLow31
Sullivan CountyVery Low31

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.