Nassau County, FL
FEMA National Risk Index scores, disaster declarations & hazard data
Nassau County has experienced 40 federally declared disasters since 1973, most recently Hurricane Milton in 2025. Its overall natural hazard risk is rated Relatively Low — lower risk than most US counties.
Nassau County's highest-rated hazards are hurricane, wildfire, and coastal flooding, with its top risk rated "Relatively Moderate" by FEMA's National Risk Index. Recorded storm events have increased 31% over the past five years compared to the prior five-year period. Community vulnerability is relatively low (25th percentile nationally), indicating stronger recovery capacity than most US counties.
Past disasters & FEMA designations
A federal disaster declaration officially designates a county for FEMA disaster assistance. Nassau County has been designated in 40 declarations since 1973, covering 8 disaster types including hurricane (20), severe storm (7), tropical storm (4).
| Year | Type | Event name |
|---|---|---|
| 2025 | Hurricane | Hurricane Milton |
| 2025 | Hurricane | Hurricane Milton |
| 2024 | Tropical Storm | Tropical Storm Debby |
| 2024 | Hurricane | Hurricane Helene |
| 2024 | Tropical Storm | Hurricane Debby |
| 2023 | Tropical Storm | Tropical Storm Nicole |
| 2023 | Tropical Storm | Tropical Storm Idalia |
| 2023 | Hurricane | Hurricane Nicole |
| 2023 | Hurricane | Hurricane Idalia |
| 2022 | Hurricane | Tropical Storm Ian |
Showing the 10 most recent of 40 total declarations since 1973.
Source: FEMA OpenFEMA Disaster Declarations Summaries. A single disaster can produce more than one record per county. Data current through September 2026.
Risk by hazard type
| Hazard | Risk rating | Risk score | Recorded events | Deaths | Prop. damage |
|---|---|---|---|---|---|
| Wildfire | Relatively Low | 86.5 | 0 | 0 | — |
| Inland Flooding | Relatively Low | 59 | 10 | 0 | $25K |
| Coastal Flooding | Relatively Moderate | 75.8 | 0 | 0 | — |
| Earthquake | Relatively Low | 62.8 | — | — | — |
| Heat Wave | Relatively Low | 71.8 | 0 | 0 | — |
| Tornado | Relatively Low | 53.6 | 5 | 0 | — |
| Hurricane | Relatively Moderate | 88.4 | 0 | 0 | — |
| Hail | Very Low | 21.8 | 14 | 0 | — |
| Strong Wind | Relatively Low | 18.6 | 0 | 0 | — |
| Winter Weather | Very Low | 7.6 | 0 | 0 | — |
| Ice Storm | Relatively Low | 53.3 | — | — | — |
| Cold Wave | Very Low | 12 | — | — | — |
| Lightning | Relatively Moderate | 71.5 | 1 | 0 | $100 |
| Drought | Very Low | 16.3 | 0 | 0 | — |
| Landslide | Very Low | 24.2 | 0 | 0 | — |
| Avalanche | Not Applicable | — | — | — | — |
| Tsunami | Insufficient Data | — | — | — | — |
| Volcanic Activity | Not Applicable | — | — | — | — |
Scores are 0–100 percentiles relative to all US counties — higher means more exposed, not that a disaster is likely this year. Event counts: NOAA Storm Events 2016–2026; earthquake counts from USGS ComCat (M3.0+, 1996–2026). See the methodology page for details.
Community vulnerability
Nassau County ranks in the 25th percentile (Low) for community vulnerability — a measure of how hard disaster impacts tend to hit residents. Higher vulnerability means more displacement, worse health outcomes, and slower recovery after a disaster.
| SVI theme | Percentile | Vulnerability level |
|---|---|---|
| Overall | 25th | Low |
| Socioeconomic status | 23rd | Very low |
| Household characteristics | 41st | Low |
| Racial & ethnic minority status | 43rd | Low |
| Housing type & transportation | 27th | Low |
Source: CDC/ATSDR Social Vulnerability Index 2022. Percentiles compare counties nationally — higher means more vulnerable relative to other counties. See CDC SVI for full methodology.
Future risk outlook
| Wildfire metric | National percentile | Level |
|---|---|---|
| Burn probability | 80th | Very High |
| Risk to homes | 81st | Very High |
| Buildings in direct exposure zone | 70.9% | — |
NOAA tracked 30 weather events in this county over 2016–2025: 13 in 2016–20 vs 17 in 2021–25 (+31% — frequency increasing).
Wildfire: USDA Forest Service Wildfire Risk to Communities (RDS-2020-0016-2) — modeled values, not annual forecasts. See wildfirerisk.org. Inland flood and heat projections pending data availability; coastal sea-level projections are available for select coastal counties below — see the data page.
Nearby counties
Frequently asked questions
What natural hazards pose the greatest risk in Nassau County?
According to the FEMA National Risk Index, the highest-risk hazards in Nassau County, Florida are hurricane, wildfire, and coastal flooding. The county's overall natural hazard risk is rated Relatively Low — lower risk than most US counties.
Has Nassau County received federal disaster declarations?
Yes. Nassau County has received 40 federal disaster declarations since 1973, including declarations in 2025. The most common disaster type on record is hurricane (20 declarations).
Has Nassau County had any FEMA disaster declarations in 2024, 2025, or 2026?
Yes. Recent federal disaster declarations for Nassau County include Hurricane Milton (2025), Hurricane Milton (2025), Tropical Storm Debby (2024), Hurricane Helene (2024), Hurricane Debby (2024). See the declarations table above for the full history since 1973.
How does Nassau County's natural hazard risk compare to nearby counties?
Among neighboring counties, Duval County, FL has the highest overall natural hazard risk (Relatively High) and Baker County, FL has the lowest (Very Low). Nassau County is rated Relatively Low overall.
How is Nassau County's composite disaster risk index calculated?
Nassau County's composite disaster risk index — officially FEMA's National Risk Index (NRI) — scores every US county on a 0–100 percentile scale across 18 natural hazard types, factoring in expected annual loss, social vulnerability, and community resilience. Nassau County's composite score of 59 means its overall natural hazard risk is higher than 59% of US counties.