FloodZoneMap.org

Nassau County, New York Flood Zones

Check an Address in Nassau County

Enter any address in Nassau County, New York to see its FEMA flood zone

The Flooding Character of Nassau County

Flash flooding from heavy rainfall events is the most frequent type of flooding recorded in Nassau County over the past 30 years, with 169 such events documented. This was evident in incidents such as the flash flooding on January 10, 2024, when a low-pressure system brought persistent rainfall, causing localized flooding and stranding vehicles. Another example occurred on July 31, 2025, where slow-moving thunderstorms resulted in similar conditions.

Coastal flooding and storm surge have also impacted the area, with 64 coastal flood events and 3 storm surge/tide events recorded in the same period. Tropical storms have also contributed, with 6 events resulting in 3 fatalities.

Homeowners in Zone A, which has the highest number of National Flood Insurance Program claims, should pay particular attention to flood risk. Properties in Zone X and Zone X_Shaded also experience significant claims, indicating a broader risk across different flood zones.

Summary generated from NOAA storm narratives and NFIP claim data for this county. Not predictive.

Read First-Hand Flood Stories from Nassau County

104 NOAA storm reports from this county describe what happened, in the words of the meteorologists who were there.

Read New York flood stories →

Flood Risk Data for Nassau County

Nassau County, New York has recorded 263 flood-related events since 1996 according to NOAA's Storm Events Database, including 169 flash floods and 21 river or area floods. The county has received 31 federal disaster declarations, 4 of which involved flooding or coastal storms. Enter any address above to check its FEMA flood zone designation.

Nassau County Disaster History

FEMA Disaster Declarations (1965–2023)

Disaster Declarations
31
Flood/Coastal Disasters
4
Hurricane Disasters
7
Latest Disaster
Severe Storm And Flooding (2023-09-28)

Source: OpenFEMA Disaster Declarations Summaries.

Recent Disaster Declarations in Nassau County

DeclarationTypeDate
Severe Storm And FloodingFloodSep 28, 2023
Remnants Of Hurricane IdaHurricaneSep 1, 2021
Hurricane HenriHurricaneAug 21, 2021
Tropical Storm IsaiasHurricaneAug 4, 2020
Covid-19BiologicalJan 20, 2020
Covid-19 PandemicBiologicalJan 20, 2020
Hurricane SandyHurricaneOct 27, 2012
Hurricane IreneHurricaneAug 26, 2011
Severe Winter Storm And SnowstormSevere StormDec 26, 2010
Severe Storms And FloodingSevere StormMar 13, 2010

Recorded Flood Events in Nassau County

NOAA Storm Events Database (1996–2025)

Total Flood Events
263
River/Area Floods
21
Flash Floods
169
Coastal/Storm Surge
67
Hurricanes/Tropical Storms
6
Total Property Damage
$19.2M
Flood Deaths
3

Source: NOAA National Weather Service Storm Events Database.

Recent Flood Events in Nassau County

TypeDateDamage
Flash FloodJul 31, 20250.00K
Flash FloodAug 18, 20240.00K
Coastal FloodJan 13, 20240.00K
Coastal FloodJan 10, 20240.00K
Flash FloodJan 10, 20240.00K
Flash FloodJan 9, 20240.00K
Flash FloodAug 6, 20240.00K
Flash FloodSep 29, 20230.00K
Coastal FloodDec 18, 2023
Flash FloodJul 21, 20220.00K

Nassau County Flood History

Flash Flood — Jul 31, 2025

A slow moving frontal boundary moved over the local area triggering heavy rainfall and thunderstorms across NJ and NYC causing flash flooding across the area resulting in vehicles being stranded and multiple road closures.

Flash Flood — Aug 18, 2024

A frontal system over the area on August 18th and into the early morning hours of August 19th allowed for the development of multiple rounds of slow moving heavy thunderstorms which resulted in widespread significant to catastrophic flash flooding for portions of Southeast New York, specifically for the north shore of Long Island. Several rounds of rain moved through during the day on August 18...

Coastal Flood — Jan 13, 2024

Strong low pressure shifted northeast through the eastern Great Lakes on January 13, 2024, sending a warm front through during the morning hours, followed quickly by a cold front. Strong winds produced by this system, combined with peaking high astronomical tides associated with a recent new moon, produced widespread moderate to major coastal flooding along the entire southeast New York coastli...

Coastal Flood — Jan 10, 2024

Strong low pressure moving northeast from the Mid Atlantic region to southern New England during the night of January 9, 2024 into the early morning hours of January 10, 2024 produced high winds, which combined with high astronomical tides associated with an upcoming new moon to produce widespread moderate to major coastal flooding along the south shore of Long Island and along the Hudson River...

Flash Flood — Jan 10, 2024

A large low pressure system impacted the area late on January 9th and into the 10th with long duration persistent moderate to heavy rainfall. In addition to widespread river flooding, some localized areas of flash flooding occurred as the heaviest rainfall associated with convection moved through. Precipitable water values of 1.2-1.4 inches were record levels for early January. The anomalous mo...

Source: NOAA National Weather Service Storm Events Database.

Nassau County NFIP Flood Insurance Claims

Total Claims Filed
42,614
Total Paid Out
$1.9B
Avg Claim
$51,118
Avg Water Depth
10.1 ft

Claims by Flood Zone

A Zones (High Risk)
29,530
V Zones (Coastal)
208
X Shaded (500-yr)
1,583
X Unshaded (Low)
964

Source: OpenFEMA NFIP Individual Claims (2.25M records analyzed).

Flood Zone Types in Nassau County

FEMA assigns flood zone designations to areas in Nassau County, New York:

AE High Risk — 1% annual chance of flooding. Insurance required.

VE Very High Risk — Coastal flooding with wave action.

X (Shaded) Moderate Risk — 500-year floodplain.

X Low Risk — Outside major floodplains.

View all flood zone types →

Flood Insurance in Nassau County

Properties in Nassau County, New York that are in FEMA-designated Special Flood Hazard Areas (zones A and V) with federally backed mortgages are required to carry flood insurance.

Even outside high-risk zones, flood insurance is recommended. From 2014 to 2024, nearly one-third of NFIP claims came from outside the high-risk Special Flood Hazard Area.

Visit FloodSmart.gov to find an agent and get a quote.