Nassau County
New York — Natural Disaster Risk Assessment
HighComposite Risk Score
National percentile: 97th
Nassau County faces high composite natural disaster risk (NRI Risk Index score 97.1, 97th national percentile), driven primarily by winter weather and ice storm exposure. Expected annual loss across all 18 hazard types is $299M.
Source: FEMA National Risk Index v1.20 · Updated December 2025
Top Hazards
All 18 Hazard Risks
| Winter Weather | Very High | 9.75 / yr | $2M |
| Ice Storm | Very High | 0.72 / yr | $4M |
| Coastal Flood | Very High | 3.83 / yr | $24M |
| Riverine Flood | High | 3.29 / yr | $184M |
| Lightning | Very High | 27.27 / yr | $3M |
| Strong Wind | High | 4.87 / yr | $4M |
| Earthquake | Medium | 0.00 / yr | $28M |
| Heat Wave | Medium | 5.82 / yr | $8M |
| Hurricane | High | 0.17 / yr | $27M |
| Cold Wave | High | 0.52 / yr | $10M |
| Tornado | Medium | 0.13 / yr | $4M |
| Landslide | Low | 0.08 / yr | $11K |
| Wildfire | Very Low | 0.00 / yr | $36K |
| Hail | Very Low | 1.67 / yr | $96K |
| Drought | Very Low | 0.81 / yr | $2K |
| Avalanche | Very Low | 0.00 / yr | $0 |
| Tsunami | Very Low | 0.00 / yr | $0 |
| Volcanic Activity | Very Low | 0.00 / yr | $0 |
Frequently Asked Questions
What is the overall natural disaster risk for Nassau County?
Nassau County has a composite FEMA National Risk Index score of 97.1 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 Nassau County?
The three highest-rated hazards are Winter Weather (Very High, $2M EAL), Ice Storm (Very High, $4M EAL), Coastal Flood (Very High, $24M EAL). These account for most of the county's expected annual losses.
How does Nassau County compare to other New York counties?
Nassau County ranks #7 of 62 New York counties for overall natural disaster risk, with a high rating.
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. Nassau County's $299M EAL is a statistical average, not a guarantee for any specific year or address.