Nassau County, Florida Natural Disaster Risk
FEMA National Risk Index assessment · FL
LowComposite Risk Score
National percentile: 59th
Nassau County faces low composite natural disaster risk (NRI Risk Index score 59.3, 59th national percentile), driven primarily by hurricane and wildfire exposure. Expected annual loss across all 18 hazard types is $25M.
Source: FEMA National Risk Index v1.20 · Updated December 2025
Risk Overview
Overall natural disaster risk in Nassau County is low, with a National Risk Index score of 59.3 out of 100 — placing it in the 59th national percentile and below the national average for natural-disaster risk. The score blends Expected Annual Loss, Social Vulnerability, and Community Resilience across all 18 FEMA hazard types.
Risk here concentrates in hurricane (tropical cyclones bringing extreme wind, rain, and storm surge) at Medium risk — $7M in expected annual loss and about 0.29 events per year; wildfire (uncontrolled fires that spread across wildland and into communities) at Low risk — $968K in expected annual loss and about 0.00 events per year; and coastal flood (seawater inundation from storm surge, high tides, and rising sea levels) at Medium risk — $2M in expected annual loss and about 3.51 events per year. Across all hazards, FEMA estimates $25M in expected annual loss for a population of 90K.
Beyond physical exposure, Nassau County has a low 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: Nassau County has received 40 federal disaster declarations since 1973, including 20 for hurricane events and 7 for severe storm events. The most recent was Hurricane Milton (hurricane), declared in October 2024.
Among 67 Florida counties, Nassau County ranks #52 for overall natural disaster risk.
Top Hazards
All 18 Hazard Risks
| Hurricane | Medium | 0.29 / yr | $7M |
| Wildfire | Low | 0.00 / yr | $968K |
| Coastal Flood | Medium | 3.51 / yr | $2M |
| Heat Wave | Low | 4.20 / yr | $1M |
| Lightning | Medium | 73.37 / yr | $615K |
| Earthquake | Low | 0.00 / yr | $626K |
| Riverine Flood | Low | 0.57 / yr | $10M |
| Tornado | Low | 0.32 / yr | $2M |
| Ice Storm | Low | 0.20 / yr | $115K |
| Landslide | Very Low | 0.08 / yr | $206 |
| Hail | Very Low | 1.78 / yr | $92K |
| Strong Wind | Low | 0.87 / yr | $192K |
| Drought | Very Low | 18.89 / yr | $1K |
| Cold Wave | Very Low | 2.68 / yr | $126K |
| Winter Weather | Very Low | 0.10 / yr | $7K |
| Avalanche | Very Low | 0.00 / yr | $0 |
| Tsunami | Very Low | 0.00 / yr | $0 |
| Volcanic Activity | Very Low | 0.00 / yr | $0 |
Disaster History
Nassau County has received 40 federal disaster declarations since 1973, most recently Hurricane Milton in October 2024. Most frequent causes: Hurricane (20), Severe Storm (7), Tropical Storm (4).
| Declared | Type | Disaster |
|---|---|---|
| October 2024 | Hurricane | Hurricane Milton |
| October 2024 | Hurricane | Hurricane Milton |
| September 2024 | Hurricane | Hurricane Helene |
| August 2024 | Tropical Storm | Hurricane Debby |
| August 2024 | Tropical Storm | Tropical Storm Debby |
| August 2023 | Hurricane | Hurricane Idalia |
| August 2023 | Tropical Storm | Tropical Storm Idalia |
| December 2022 | Hurricane | Hurricane Nicole |
| November 2022 | Tropical Storm | Tropical Storm Nicole |
| September 2022 | Hurricane | Hurricane Ian |
Showing the 10 most recent of 40 declarations.
Source: FEMA Disaster Declarations Summaries (OpenFEMA).
Frequently Asked Questions
What is the overall natural disaster risk for Nassau County?
Nassau County has a composite FEMA National Risk Index score of 59.3 out of 100, placing it in the Low category and the 59th 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 Hurricane (Medium, $7M EAL), Wildfire (Low, $968K EAL), Coastal Flood (Medium, $2M EAL). These account for most of the county's expected annual losses.
How does Nassau County compare to other Florida counties?
Nassau County ranks #52 of 67 Florida counties for overall natural disaster risk, with a low rating.
How many federally declared disasters has Nassau County had?
FEMA records 40 federal disaster declarations for Nassau County since 1973, most often 20 for hurricane events and 7 for severe storm events. The most recent was Hurricane Milton, 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. Nassau County's $25M EAL is a statistical average, not a guarantee for any specific year or address.