Great River is calmer than 85% of U.S. communities
Most of the natural-hazard damage FEMA expects in Great River comes from inland flooding, and overall the risk is very low for a U.S. community. Flood insurance has paid 22 claims here since 1983.
What stands out about Great River’s weather risks
Read from FEMA’s records below. The page puts what stands out first.
How exposed is Great River?
FEMA expects yearly storm and flood damage to homes and buildings here to be higher than in 15% of U.S. communities, mostly from inland flooding.
Calmer than 1,226 of the 1,524 New York towns we cover.
Great River covers 1 census tract, combined by population.
What Great River faces
Each hazard’s share of the damage FEMA expects here, and how it compares with the rest of the country.
Inland flooding
Hurricanes
Coastal flooding
Earthquakes
Does Great River flood? Sometimes: 22 flood claims since 1983
Every paid claim on a federal flood insurance policy in Great River, from FEMA’s records.
- Hurricane Sandy9 claims · $820K
- The March 2010 nor’easter4 claims · $13K
- The December Storm - nor’easter3 claims · $2K
Great River isn’t in FEMA’s Community Rating System, which cuts flood insurance up to 45% in towns that do extra flood-proofing.
Insurance rates: Suffolk County.Federal disasters declared here
None of the disasters declared for Suffolk County shows FEMA aid or repair money reaching Great River itself in FEMA’s records.
Suffolk County has had 28 natural disasters declared since 1953, most often hurricanes and severe storms.
Get ready for what Great River actually faces
A short kit for its top hazards, what to check before you buy, and where neighbors get alerts.
- Turn around at flooded roads: a foot of moving water can carry off a car.
- Flood insurance usually takes 30 days to start, so buy it before the forecast.
- Keep papers and medicines up high, in a grab-and-go bag.
- The season runs June through November and peaks from mid-August to mid-October.
- Bring in porch furniture and anything the wind can throw.
- Fill the gas tank and charge phones before the storm arrives.
- Know your evacuation zone and the way off the coast.
- Storm surge comes fast: leave when you’re told, not when the water arrives.
- Move cars to high ground before king tides and nor’easters.
- Look up the address on FEMA’s flood map.
- Ask the seller or landlord whether it has ever flooded, and what flood insurance costs there.
- Get a flood insurance quote early: policies usually start 30 days after you buy.
Know where neighbors sign up for alerts? Add it to the Handbook so everyone has it.
Great River and its neighbors
Great River ranks 2nd calmest of 3 towns around it. Tap a town to see its hazards.
| Town | Rating | Mostly | Flood claims |
|---|---|---|---|
| Brookhaven | Low | inland flooding | 3,825 |
| Great River | Very low | inland flooding | 22 |
| Islip | Very low | inland flooding | 4,791 |
Rating = expected yearly storm and flood damage as a share of what’s there, vs. U.S. communities. Flood claims = paid federal flood insurance claims on record.
Most disasters here begin in August–September
The month each of Suffolk County’s 28 declared disasters began, since 1953.
What these numbers can and can’t tell you
- An average, not a forecast. FEMA’s National Risk Index estimates the damage 18 kinds of natural hazards cause in a typical year, from decades of records and models. A quiet decade can follow a bad year.
- Compared by rate. “Higher than N%” compares yearly damage as a share of what’s there, so a big city isn’t rated riskier just for having more buildings.
- Money that reached town. Flood claims are matched to Great River’s own flood-insurance community (here, the census tracts inside it); household aid to the registrant’s city; repair grants to Great River.
- It follows property value. FEMA’s model weighs damage to buildings, so a place that recently lost many homes can rate lower than it feels. Across Great River, expected losses total about $541K a year, counting buildings, people and crops.
Storm stories
Memories, warnings and help from neighbors in Great River.
Your answer becomes a post in Town Square.
Sources: FEMA National Risk Index (December 2025); OpenFEMA: NFIP redacted claims, multiple-loss properties, community status book and residential penetration rates, housing assistance (owners and renters), public assistance funded projects, hazard mitigation properties and disaster declarations. Census tracts: U.S. Census Bureau. Weather alerts: National Weather Service. Preparedness tips: Ready.gov. An average of past damage, not a forecast.