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Nassau County, New York

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

Relatively High overall risk
7th of 62highest risk in New York
$299Mexpected losses a year
27federal declarations
1 in 10homes with flood insurance
Photo: U.S. Geological Survey, public domain

Nassau County, New York has a relatively high overall risk from natural hazards in FEMA's National Risk Index. Its risk score is higher than 97% of US counties. It ranks 7th of 62 counties in New York. The costliest hazards here are inland flooding, earthquakes and hurricanes. FEMA estimates about $299 million a year in expected losses, or roughly $214 per resident. Since 1965 it has been included in 27 federal disaster or emergency declarations for natural events (20 major disasters). The most recent was in January 2024 (severe storm and flooding). About 1 in 10 homes here carry federal flood insurance (35,824 policies). Since 1978, federal flood insurance has paid about $2.3 billion on 51,523 claims here, including $2.0 billion for floods in 2012.

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

Top risks in Nassau County

$184 million a yearExpected losses. Damaging events about 3 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.

Earthquake

Moderate
$28 million a yearExpected losses. Damaging events about once every 530 years.
  • Ask whether an older house is bolted to its foundation.
  • Consider separate earthquake insurance where risk is high.
$27.1 million a yearExpected losses. Damaging events about once every 6 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.
HazardRatingScoreExpected loss a year
Inland floodingHigh98.2
$184M
EarthquakeModerate96.5
$28M
HurricaneHigh95.4
$27M
Coastal floodingVery High98.4
$24M
Cold waveHigh92.7
$10M
Heat waveModerate96.0
$8M
Strong windHigh97.1
$4M
Ice stormVery High98.7
$4M
TornadoModerate76.2
$4M
LightningVery High97.3
$3M
Winter weatherVery High98.9
$2M
HailVery Low23.4
$96K
WildfireVery Low43.6
$36K
LandslideLow75.9
$11K
DroughtVery Low17.5
$2K

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 low and community resilience is very high in FEMA's measures.

Federal disaster history

Recent disasters nationwide ›

Declarations by decade

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

By type

Hurricane12
Severe Storm6
Flood4
Snowstorm3
Drought1
Fire1

Most recent

Jan 30, 2024Severe Storm and FloodingMajor disaster
Sep 5, 2021Remnants of Hurricane IdaMajor disaster
Sep 2, 2021Remnants of Hurricane IdaEmergency
Aug 22, 2021Hurricane HenriEmergency
Oct 2, 2020Tropical Storm IsaiasMajor disaster
Oct 30, 2012Hurricane SandyMajor disaster
Oct 28, 2012Hurricane SandyEmergency
Aug 31, 2011Hurricane IreneMajor disaster
Aug 26, 2011Hurricane IreneEmergency
Feb 18, 2011Severe Winter Storm and SnowstormMajor disaster
Show all 27
Apr 16, 2010Severe Storms and FloodingMajor disaster
Dec 31, 2009Severe Storms and Flooding Assoc W Td Ida & Nor'EasterMajor disaster
Sep 30, 2005Hurricane Katrina EvacuationEmergency
Aug 3, 2004Severe Storms and FloodingMajor disaster
Mar 27, 2003SnowEmergency
Sep 11, 2001Fires and ExplosionsMajor disaster
Sep 19, 1999Hurricane Floyd Major Disaster DeclarationsMajor disaster
Sep 11, 1998Ny - Severe Wx, Sept 7, 1998Major disaster
Nov 19, 1996Severe Storms, Flooding, Heavy Rains, High WindsMajor disaster
Jan 12, 1996Blizzard of 96 (Severe Snow Storm)Major disaster
Mar 17, 1993Severe BlizzardEmergency
Dec 21, 1992Coastal Storm, High Tides, Heavy Rain, & FloodingMajor disaster
Oct 18, 1985Hurricane GloriaMajor disaster
Apr 17, 1984Coastal Storms & FloodingMajor disaster
Sep 3, 1976Hurricane BelleMajor disaster
Sep 13, 1971Severe Storms & FloodingMajor disaster
Aug 18, 1965Water ShortageMajor disaster

New York also had 12 statewide declarations that did not name single counties.

Storm history since 1962

Tornado risk by county ›

The National Weather Service has logged 585 storm reports in Nassau County since 1962, with 8 deaths and 60 injuries and about $24.9 million in reported damage. The strongest on record here was an F2 tornado on September 7, 1998 near Lynbrook.

9tornadoes
81hail reports, largest 3 inches
250damaging thunderstorm winds
190floods and flash floods

Strongest tornadoes

DateStrengthNearHurt / killed
Sep 7, 1998F2Lynbrook6 / 0
Sep 27, 1970F2–0 / 0
Sep 18, 1973F2–0 / 0
Aug 12, 2005F1Glen Cove0 / 0
Jul 23, 1995F1–0 / 0

Most damaging storms

DateTypeNearDamage
Oct 14, 2005Flash FloodCountywide$11M
Sep 1, 2021Flash FloodKings Pt$8M
Sep 7, 1998Thunderstorm WindCountywide$3M
Sep 7, 1998TornadoLynbrook$1M
Jun 26, 2002LightningBethpage$500K
Nov 13, 2021TornadoHewlett$300K

Source: NOAA Storm Events Database, county-based reports through Jun 6, 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 1861, 8 hurricanes and 22 tropical storms have passed within 65 miles of the center of Nassau County, 16 of them since 1950. The strongest was an unnamed hurricane in 1938, with top winds near 120 mph about 62 miles away.

8hurricanes
1major hurricanes (Category 3+)
22tropical storms
2021most recent: Elsa

Strongest storms nearby

DateStormStrengthClosest
Sep 21, 1938UnnamedCategory 3, 120 mph62 mi
Sep 14, 1944UnnamedCategory 2, 105 mph61 mi
Sep 12, 1960DonnaCategory 2, 100 mph46 mi
Sep 27, 1985GloriaCategory 1, 90 mph60 mi
Aug 24, 1893UnnamedCategory 1, 90 mph53 mi
Oct 10, 1894UnnamedCategory 1, 85 mph62 mi

Most recent storms

DateStormStrengthClosest
Jul 9, 2021ElsaTropical storm, 60 mph52 mi
Jul 10, 2020FayTropical storm, 45 mph60 mi
Aug 28, 2011IreneTropical storm, 65 mph60 mi
Sep 7, 2008HannaTropical storm, 50 mph37 mi
Sep 16, 1999FloydTropical storm, 60 mph40 mi
Jul 13, 1996BerthaTropical storm, 70 mph60 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 Nassau County

Check your address flood zone ›
9.7%of homes have federal flood insurance (35,824 policies)
76.2%of homes in mapped high-risk flood zones are insured
$2.3 billionpaid on 51,523 flood claims since 1978
2012costliest year, with $2 billion 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 Nassau County

$684,700median home value (New York $423,800, US $332,700)
1955median year homes were built (New York 1959, US 1980)
85%of homes built before 1980, before many modern wind, quake and flood building rules
0.2%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; 479,044 housing units.

Compare in New York

All 62 ›
Largest countiesOverall riskTop hazard
Kings CountyHighInland flooding
Queens CountyHighInland flooding
New York CountyHighInland flooding
Suffolk CountyHighInland flooding
Bronx CountyHighInland flooding
Nassau CountyHighInland flooding
Westchester CountyHighInland flooding
Erie CountyHighInland flooding

Neighboring counties

CountyOverall riskDeclarations
Queens CountyHigh21
Suffolk CountyHigh32
Bronx CountyHigh16
Westchester CountyHigh28
Western Connecticut Planning Region, CTHigh33

Common questions about Nassau County

What is the biggest natural hazard in Nassau County?

Inland flooding has the highest expected yearly losses in Nassau County, about $184 million a year in FEMA's estimate. Earthquake is second at $28 million.

How many federal disasters has Nassau County had?

Nassau County has been included in 27 federal disaster or emergency declarations for natural events since 1965, including 20 major disasters. The most recent was Severe Storm and Flooding in January 2024.

Is Nassau County a high-risk place to live?

Its overall rating is Relatively High, 7th highest of 62 in New York. 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 Nassau County?

Standard home insurance does not cover flooding. About 1 in 10 homes in Nassau 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 Nassau County had?

NOAA records list 9 tornadoes in Nassau County since 1950. The strongest was an F2 tornado on September 7, 1998 near Lynbrook. The weather service has also logged 81 hail reports and 190 floods here.

How many hurricanes have hit Nassau County?

NOAA's hurricane records show 8 hurricanes and 22 tropical storms passing within 65 miles of the center of Nassau County, including 1 major hurricane (Category 3 or stronger). The strongest was an unnamed hurricane in 1938, with winds near 120 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.