Westchester County, New York Natural Disaster Risk
FEMA National Risk Index assessment · NY
HighComposite Risk Score
National percentile: 96th
Westchester County faces high composite natural disaster risk (NRI Risk Index score 96.2, 96th national percentile), driven primarily by strong wind and riverine flood exposure. Expected annual loss across all 18 hazard types is $210M.
Source: FEMA National Risk Index v1.20 · Updated December 2025
Risk Overview
Overall natural disaster risk in Westchester County is high, with a National Risk Index score of 96.2 out of 100 — placing it in the 96th 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 strong wind (damaging straight-line winds outside of tornadoes and hurricanes) at Very High risk — $8M in expected annual loss and about 4.97 events per year; riverine flood (rivers and streams overflowing their banks after heavy rain or snowmelt) at High risk — $148M in expected annual loss and about 4.14 events per year; and winter weather (heavy snow, blizzards, and hazardous winter conditions) at Very High risk — $1M in expected annual loss and about 12.50 events per year. Across all hazards, FEMA estimates $210M in expected annual loss for a population of 1M.
Beyond physical exposure, Westchester County has a medium social vulnerability rating (how susceptible the population is to harm) and a 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.
History supports the rating: Westchester County has received 32 federal disaster declarations since 1965, including 11 for hurricane events and 6 for flood events. The most recent was Severe Storm and Flooding (flood), declared in January 2024.
Among 62 New York counties, Westchester County ranks #8 for overall natural disaster risk.
Top Hazards
All 18 Hazard Risks
| Strong Wind | Very High | 4.97 / yr | $8M |
| Riverine Flood | High | 4.14 / yr | $148M |
| Winter Weather | Very High | 12.50 / yr | $1M |
| Lightning | Very High | 28.70 / yr | $3M |
| Heat Wave | Medium | 6.18 / yr | $7M |
| Earthquake | Medium | 0.00 / yr | $13M |
| Cold Wave | High | 1.02 / yr | $9M |
| Hurricane | High | 0.14 / yr | $15M |
| Landslide | Medium | 0.52 / yr | $85K |
| Ice Storm | High | 1.27 / yr | $927K |
| Coastal Flood | Medium | 5.42 / yr | $2M |
| Tornado | Medium | 0.16 / yr | $3M |
| Wildfire | Very Low | 0.00 / yr | $66K |
| Hail | Very Low | 2.31 / yr | $126K |
| Drought | Very Low | 0.97 / yr | $26K |
| Avalanche | Very Low | 0.01 / yr | $104 |
| Tsunami | Very Low | 0.00 / yr | $0 |
| Volcanic Activity | Very Low | 0.00 / yr | $0 |
Disaster History
Westchester County has received 32 federal disaster declarations since 1965, most recently Severe Storm and Flooding in January 2024. Most frequent causes: Hurricane (11), Flood (6), Severe Storm (6).
| Declared | Type | Disaster |
|---|---|---|
| January 2024 | Flood | Severe Storm and Flooding |
| 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 |
| October 2012 | Hurricane | Hurricane Sandy |
| October 2012 | Hurricane | Hurricane Sandy |
| August 2011 | Hurricane | Hurricane Irene |
Showing the 10 most recent of 32 declarations.
Source: FEMA Disaster Declarations Summaries (OpenFEMA).
Frequently Asked Questions
What is the overall natural disaster risk for Westchester County?
Westchester County has a composite FEMA National Risk Index score of 96.2 out of 100, placing it in the High category and the 96th national percentile. This combines Expected Annual Loss, Social Vulnerability, and Community Resilience across 18 hazard types.
What are the top natural hazards in Westchester County?
The three highest-rated hazards are Strong Wind (Very High, $8M EAL), Riverine Flood (High, $148M EAL), Winter Weather (Very High, $1M EAL). These account for most of the county's expected annual losses.
How does Westchester County compare to other New York counties?
Westchester County ranks #8 of 62 New York counties for overall natural disaster risk, with a high rating.
How many federally declared disasters has Westchester County had?
FEMA records 32 federal disaster declarations for Westchester County since 1965, most often 11 for hurricane events and 6 for flood events. The most recent was Severe Storm and Flooding, declared in January 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. Westchester County's $210M EAL is a statistical average, not a guarantee for any specific year or address.