Suffolk County, New York Natural Disaster Risk
FEMA National Risk Index assessment · NY
HighComposite Risk Score
National percentile: 97th
Suffolk County faces high composite natural disaster risk (NRI Risk Index score 97.3, 97th national percentile), driven primarily by winter weather and coastal flood exposure. Expected annual loss across all 18 hazard types is $321M.
Source: FEMA National Risk Index v1.20 · Updated December 2025
Risk Overview
FEMA's National Risk Index rates Suffolk County at high composite risk, with a National Risk Index score of 97.3 out of 100 — placing it in the 97th national percentile and in the upper tier of natural-disaster risk nationally. The score blends Expected Annual Loss, Social Vulnerability, and Community Resilience across all 18 FEMA hazard types.
The county's risk is driven primarily by winter weather (heavy snow, blizzards, and hazardous winter conditions) at Very High risk — $2M in expected annual loss and about 10.34 events per year; coastal flood (seawater inundation from storm surge, high tides, and rising sea levels) at Very High risk — $25M in expected annual loss and about 3.79 events per year; and riverine flood (rivers and streams overflowing their banks after heavy rain or snowmelt) at High risk — $193M in expected annual loss and about 3.54 events per year. Across all hazards, FEMA estimates $321M in expected annual loss for a population of 1.52M.
Beyond physical exposure, Suffolk County has a low social vulnerability rating (how susceptible the population is to harm) and a very high community resilience rating (its capacity to prepare for and recover from disasters). A less vulnerable population paired with strong resilience helps the community absorb and recover from events.
The federal record bears this out: Suffolk County has received 36 federal disaster declarations since 1965, including 13 for hurricane events and 9 for severe storm events. The most recent was Severe Storm and Flooding (severe storm), declared in October 2024.
Among 62 New York counties, Suffolk County ranks #6 for overall natural disaster risk.
Top Hazards
All 18 Hazard Risks
| Winter Weather | Very High | 10.34 / yr | $2M |
| Coastal Flood | Very High | 3.79 / yr | $25M |
| Riverine Flood | High | 3.54 / yr | $193M |
| Strong Wind | High | 3.17 / yr | $6M |
| Lightning | Very High | 23.80 / yr | $3M |
| Hurricane | High | 0.20 / yr | $43M |
| Ice Storm | Very High | 0.67 / yr | $2M |
| Earthquake | Medium | 0.00 / yr | $21M |
| Cold Wave | High | 0.55 / yr | $14M |
| Heat Wave | Medium | 3.87 / yr | $7M |
| Landslide | Low | 0.18 / yr | $33K |
| Tornado | Medium | 0.47 / yr | $4M |
| Wildfire | Low | 0.00 / yr | $265K |
| Hail | Low | 1.29 / yr | $186K |
| Drought | Very Low | 0.14 / yr | $686 |
| Avalanche | Very Low | 0.00 / yr | $0 |
| Tsunami | Very Low | 0.00 / yr | $0 |
| Volcanic Activity | Very Low | 0.00 / yr | $0 |
Disaster History
Suffolk County has received 36 federal disaster declarations since 1965, most recently Severe Storm and Flooding in October 2024. Most frequent causes: Hurricane (13), Severe Storm (9), Snowstorm (5).
| Declared | Type | Disaster |
|---|---|---|
| October 2024 | Severe Storm | Severe Storm and Flooding |
| August 2024 | Severe Storm | Severe Storm and Flooding |
| March 2023 | Snowstorm | Severe Winter Storm and Snowstorm |
| September 2021 | Hurricane | Remnants of Hurricane Ida |
| September 2021 | Hurricane | Remnants of Hurricane Ida |
| August 2021 | Hurricane | Hurricane Henri |
| October 2020 | Hurricane | Tropical Storm Isaias |
| March 2020 | Biological | Covid-19 Pandemic |
| March 2020 | Biological | Covid-19 |
| July 2017 | Snowstorm | Severe Winter Storm and Snowstorm |
Showing the 10 most recent of 36 declarations.
Source: FEMA Disaster Declarations Summaries (OpenFEMA).
Frequently Asked Questions
What is the overall natural disaster risk for Suffolk County?
Suffolk County has a composite FEMA National Risk Index score of 97.3 out of 100, placing it in the High category and the 97th national percentile. This combines Expected Annual Loss, Social Vulnerability, and Community Resilience across 18 hazard types.
What are the top natural hazards in Suffolk County?
The three highest-rated hazards are Winter Weather (Very High, $2M EAL), Coastal Flood (Very High, $25M EAL), Riverine Flood (High, $193M EAL). These account for most of the county's expected annual losses.
How does Suffolk County compare to other New York counties?
Suffolk County ranks #6 of 62 New York counties for overall natural disaster risk, with a high rating.
How many federally declared disasters has Suffolk County had?
FEMA records 36 federal disaster declarations for Suffolk County since 1965, most often 13 for hurricane events and 9 for severe storm events. The most recent was Severe Storm and Flooding, declared in October 2024.
What does Expected Annual Loss (EAL) mean?
EAL is FEMA's estimate of average annual dollar losses from natural hazards, calculated from historical event data and exposure models. Suffolk County's $321M EAL is a statistical average, not a guarantee for any specific year or address.