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Coos County, New Hampshire

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

Relatively Low overall risk
5th of 10highest risk in New Hampshire
$27Mexpected losses a year
26federal declarations
1 in 167homes with flood insurance
Photo: U.S. Geological Survey, public domain

Coos County, New Hampshire has a relatively low overall risk from natural hazards in FEMA's National Risk Index. Its risk score is higher than 73% of US counties. It ranks 5th of 10 counties in New Hampshire. The costliest hazards here are inland flooding, cold waves and avalanches. FEMA estimates about $27 million a year in expected losses, or roughly $865 per resident. Since 1973 it has been included in 26 federal disaster or emergency declarations for natural events (16 major disasters). The most recent was in August 2024 (severe storm and flooding). Fewer than 1 in 100 homes here carry federal flood insurance (84 policies). Since 1978, federal flood insurance has paid about $669,000 on 95 claims here.

FEMA National Risk Index December 2025; OpenFEMA declarations to Nov 6, 2026; NFIP records. Updated November 6, 2026.

Top risks in Coos County

$15.1 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.

Cold wave

Moderate
$5 million a yearExpected losses. Damaging events about 7 times a year.
  • Insulate pipes in outside walls, crawl spaces and garages.
  • Know how to shut off the main water valve.

Avalanche

Very High
$4.6 million a yearExpected losses. Damaging events about once every 4 years.
  • Check avalanche forecasts before backcountry trips.
  • Ask about slide paths near mountain homes.
HazardRatingScoreExpected loss a year
Inland floodingModerate77.6
$15M
Cold waveModerate87.4
$5M
AvalancheVery High97.5
$5M
HurricaneLow77.1
$1M
Winter weatherHigh88.4
$312K
EarthquakeVery Low49.0
$222K
LightningLow52.4
$219K
Strong windLow22.8
$182K
Ice stormModerate69.1
$180K
TornadoVery Low10.6
$63K
Heat waveVery Low12.7
$24K
LandslideLow81.5
$16K
HailVery Low6.1
$15K
WildfireVery Low16.4
$5K

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 relatively moderate and community resilience is relatively moderate in FEMA's measures.

Federal disaster history

Recent disasters nationwide ›

Declarations by decade

Federal declarations for natural events that included Coos County. 2020s bar runs to November 2026.

By type

Severe Storm10
Flood6
Hurricane5
Snowstorm4
Severe Ice Storm1

Most recent

Aug 20, 2024Severe Storm and FloodingMajor disaster
Feb 27, 2024Severe Storm and FloodingMajor disaster
Sep 14, 2023Severe Storms and FloodingMajor disaster
Mar 15, 2023Severe Storm and FloodingMajor disaster
Jan 2, 2018Severe Storm and FloodingMajor disaster
Aug 9, 2017Severe Storms and FloodingMajor disaster
Nov 28, 2012Hurricane SandyMajor disaster
Oct 30, 2012Hurricane SandyEmergency
Nov 1, 2011Severe StormEmergency
Sep 3, 2011Tropical Storm IreneMajor disaster
Show all 26
Aug 27, 2011Hurricane IreneEmergency
Jul 22, 2011Severe Storms and FloodingMajor disaster
Jan 2, 2009Severe Winter StormMajor disaster
Dec 13, 2008Severe Winter StormEmergency
Sep 5, 2008Severe Storms and FloodingMajor disaster
Apr 27, 2007Severe Storms and FloodingMajor disaster
Sep 19, 2005Hurricane Katrina EvacuationEmergency
Mar 30, 2005Record SnowEmergency
Jan 15, 2004SnowEmergency
Mar 28, 2001SnowEmergency
Jan 15, 1998Severe Ice Storm, Rains and High WindsMajor disaster
Jan 3, 1996Excessive Rainfall, High Winds, and FloodingMajor disaster
Mar 16, 1993Blizzards, High Winds & Record SnowfallEmergency
Aug 29, 1990Severe Storms & FloodingMajor disaster
Mar 15, 1979FloodingEmergency
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 377 storm reports in Coos County since 1955, with 2 deaths and 41 injuries and about $14.9 million in reported damage. The strongest on record here was an F0 tornado on August 8, 1980.

8tornadoes
65hail reports, largest 2 inches
185damaging thunderstorm winds
111floods and flash floods

Strongest tornadoes

DateStrengthNearHurt / killed
Aug 8, 1980F0–0 / 0
Aug 27, 1974F0–0 / 0
Jul 2, 1994F0–0 / 0
Jun 5, 2010EF0Gorham Station0 / 0
Jul 26, 2011EF0Colebrook Arpt0 / 0

Most damaging storms

DateTypeNearDamage
Aug 28, 2011Flash FloodGorham Libby Fld Arp$7M
Apr 15, 2014FloodTinkerville$2M
May 26, 2011Flash FloodDalton$716K
Apr 16, 2007FloodBerlin$700K
Aug 31, 1993Thunderstorm WindCountywide$500K
Aug 7, 2008Flash FloodPittsburg$500K

Source: NOAA Storm Events Database, county-based reports through Jul 16, 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 1858, 1 hurricane and 5 tropical storms have passed within 65 miles of the center of Coos County, 3 of them since 1950. The strongest was an unnamed hurricane in 1869, with top winds near 80 mph about 54 miles away.

1hurricanes
0major hurricanes (Category 3+)
5tropical storms
1971most recent: Doria

Strongest storms nearby

DateStormStrengthClosest
Sep 9, 1869UnnamedCategory 1, 80 mph54 mi
Sep 13, 1960DonnaTropical storm, 70 mph59 mi
Sep 16, 1858UnnamedTropical storm, 65 mph47 mi
Aug 29, 1893UnnamedTropical storm, 60 mph51 mi
Aug 28, 1971DoriaTropical storm, 50 mph64 mi
Jul 31, 1960BrendaTropical storm, 45 mph52 mi

Most recent storms

DateStormStrengthClosest
Aug 28, 1971DoriaTropical storm, 50 mph64 mi
Sep 13, 1960DonnaTropical storm, 70 mph59 mi
Jul 31, 1960BrendaTropical storm, 45 mph52 mi
Aug 29, 1893UnnamedTropical storm, 60 mph51 mi
Sep 9, 1869UnnamedCategory 1, 80 mph54 mi
Sep 16, 1858UnnamedTropical storm, 65 mph47 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 Coos County

Check your address flood zone ›
0.6%of homes have federal flood insurance (84 policies)
11.2%of homes in mapped high-risk flood zones are insured
$669,305paid on 95 flood claims since 1978
2023costliest year, with $163,880 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 Coos County

$188,900median home value (New Hampshire $402,500, US $332,700)
1969median year homes were built (New Hampshire 1979, US 1980)
64%of homes built before 1980, before many modern wind, quake and flood building rules
10.1%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; 20,637 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
Grafton CountyModerate38
Oxford County, MELow35
Carroll CountyLow34
Essex County, VTVery Low28

Common questions about Coos County

What is the biggest natural hazard in Coos County?

Inland flooding has the highest expected yearly losses in Coos County, about $15.1 million a year in FEMA's estimate. Cold wave is second at $5 million.

How many federal disasters has Coos County had?

Coos County has been included in 26 federal disaster or emergency declarations for natural events since 1973, including 16 major disasters. The most recent was Severe Storm and Flooding in August 2024.

Is Coos County a high-risk place to live?

Its overall rating is Relatively Low, 5th 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 Coos County?

Standard home insurance does not cover flooding. About 1 in 167 homes in Coos 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 Coos County had?

NOAA records list 8 tornadoes in Coos County since 1950. The strongest was an F0 tornado on August 8, 1980. The weather service has also logged 65 hail reports and 111 floods here.

How many hurricanes have hit Coos County?

NOAA's hurricane records show 1 hurricane and 5 tropical storms passing within 65 miles of the center of Coos County. The strongest was an unnamed hurricane in 1869, with winds near 80 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.