Nassau County, Florida: Natural Disaster Risk and History
Nassau County, Florida has a Relatively Low natural-hazard risk rating in FEMA's National Risk Index (v1.20, December 2025): a score of 59.3 out of 100, higher than about 59% of US counties, with hurricanes, wildfires and coastal flooding scoring highest of its 18 hazards and $25 million a year in expected losses.
OpenFEMA lists 38 federal disaster declarations that included Nassau County since 1973, not counting 2 for COVID-19; the latest is DR-4834-FL (Hurricane Milton, declared 11 October 2024). NOAA's Storm Prediction Center recorded 32 tornadoes touching Nassau County from 1950 to 2025.
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Population 90,123 Buildings worth $16 billion Area 733 sq mi Risk rank in Florida 52 of 67 FIPS 12089
All 18 hazards, highest risk first
FEMA National Risk Index| Hazard | Risk rating | Score | Expected loss a year | How often | Events in record |
|---|---|---|---|---|---|
| Hurricane | Relatively Moderate | 88.4 | $6.8 million | about once every 3.5 years | 107 |
| Wildfire | Relatively Low | 86.5 | $967,891 | about once every 375 years | — |
| Coastal flooding | Relatively Moderate | 75.8 | $2.0 million | about 3.5 a year | — |
| Heat wave | Relatively Low | 71.8 | $1.2 million | about 4.2 a year | 67 |
| Lightning | Relatively Moderate | 71.5 | $615,294 | about 73 a year | 133,191 strikes |
| Earthquake | Relatively Low | 62.8 | $626,318 | about once every 847 years | — |
| Inland flooding | Relatively Low | 59.0 | $10 million | about once every 1.8 years | 16 |
| Tornado | Relatively Low | 53.6 | $1.6 million | about once every 3.1 years | 21 |
| Ice storm | Relatively Low | 53.3 | $114,902 | about once every 4.9 years | 13 |
| Landslide | Very Low | 24.2 | $206 | about once every 12 years | — |
| Hail | Very Low | 21.8 | $91,958 | about 1.8 a year | 69 |
| Strong wind | Relatively Low | 18.6 | $192,445 | about once every 1.1 years | 31 |
| Drought | Very Low | 16.3 | $1,445 | about 19 a year | 700 |
| Cold wave | Very Low | 12.0 | $125,662 | about 2.7 a year | 46 |
| Winter weather | Very Low | 7.6 | $6,652 | about once every 9.8 years | 1.8 |
| Avalanche | Not Applicable | — | — | — | — |
| Tsunami | Insufficient Data | — | — | — | — |
| Volcanic activity | Not Applicable | — | — | — | — |
Score: FEMA's percentile among US counties that face the hazard (higher = more risk). Expected loss: FEMA's modelled average yearly loss to buildings, people (as a statistical value) and crops. How often: FEMA's annualised frequency of the hazard in the county; for some hazards it counts event-days, so it is a rough guide, not a forecast. "Not Applicable" means FEMA does not model that hazard here.
Federal disaster declarations 38
Most common: Hurricane 20, Severe Storm 7, Tropical Storm 4, Fire 4.
| Decade | Declarations | Incident types |
|---|---|---|
| 1970s | 1 | Flood |
| 1990s | 9 | Fire ×3, Severe Storm ×3, Hurricane ×2, Tornado |
| 2000s | 8 | Hurricane ×4, Severe Storm ×2, Freezing, Fire |
| 2010s | 7 | Hurricane ×6, Severe Storm |
| 2020s | 13 | Hurricane ×8, Tropical Storm ×4, Severe Storm |
The last 10
Widest declarations that included Nassau County
- Hurricane Ian (2022, DR-4673-FL): 67 Florida counties designated.
- Tropical Storm Ian (2022, EM-3584-FL): 67 Florida counties designated.
- Hurricane Dorian (2019, EM-3419-FL): 67 Florida counties designated.
Named storms in its declarations: Hurricane Milton (2024), Hurricane Helene (2024), Hurricane Debby (2024), Tropical Storm Debby (2024), Hurricane Idalia (2023), Tropical Storm Idalia (2023), Hurricane Nicole (2022), Tropical Storm Nicole (2022), Hurricane Ian (2022), Tropical Storm Ian (2022), Tropical Storm Elsa (2021), Hurricane Isaias (2020), Hurricane Dorian (2019), Hurricane Irma (2017), Hurricane Matthew (2016), Tropical Storm Debby (2012), Tropical Storm Fay (2008), Hurricane Katrina (2005), Hurricane Jeanne (2004), Hurricane Frances (2004), Tropical Storm Bonnie (2004), Hurricane Floyd (1999), Tropical Storm Josephine (1996).
Not counted above: 2 COVID-19 ("Biological") declarations — in 2020 every US county was included. Florida also had 31 statewide declarations with no county list.
Tornado record since 1950 32
| Tornadoes touching the county | 32 |
|---|---|
| Strongest-rated | (E)F1 ×8 |
| Peak month | September (8) |
| Deadliest | 25 Feb 1992, F1, 0.5 mi path, 0 killed, 4 injured |
| Longest path | 25 Apr 1973, F1, 12.1 mi path |
| Most recent | 3 Sep 2024, EF0, 0.1 mi path |
| Deaths / injuries on those paths | 0 / 4 |
| Rating | (E)F0 | (E)F1 | (E)F2 | (E)F3 | (E)F4 | (E)F5 | Unrated |
|---|---|---|---|---|---|---|---|
| Count | 24 | 8 | 0 | 0 | 0 | 0 | 0 |
| Decade | 1950s | 1960s | 1970s | 1980s | 1990s | 2000s | 2010s | 2020s |
|---|---|---|---|---|---|---|---|---|
| Count | 0 | 1 | 11 | 5 | 3 | 5 | 5 | 2 |
Deaths and injuries are for each tornado's whole path, which can run beyond this county. F-scale ratings before February 2007, Enhanced Fujita (EF) after.
How Nassau County compares with its 5 nearest counties
| County | Distance | Overall risk | Score | Top hazard |
|---|---|---|---|---|
| Nassau County (this page) | — | Relatively Low | 59.3 | Hurricane |
| Duval County | 34 km | Relatively High | 97.2 | Cold wave |
| Charlton County, GA | 37 km | Very Low | 26.7 | Hurricane |
| Camden County, GA | 38 km | Relatively Low | 54.5 | Hurricane |
| Baker County | 55 km | Very Low | 13.3 | Wildfire |
| Brantley County, GA | 67 km | Very Low | 18.3 | Hurricane |
Nearest by distance between county centres. Every county in Florida, ranked.
Vulnerability and resilience
| Social vulnerability | Relatively Low 20.5 |
|---|---|
| Community resilience | Relatively High 75.6 |
| Community risk factor | 0.89 |
| Expected annual loss, all hazards | $25 million |
FEMA scales expected losses up where social vulnerability is high (people who may find it harder to prepare, evacuate or recover) and down where community resilience is high. A factor above 1 raises the risk score. For social vulnerability a high rating is worse; for resilience a high rating is better.
Prepare for Nassau County's main hazards
- Right now: National Weather Service alerts for Florida · all official warnings on Global Incident Tracker.
- Hurricane: Is there a hurricane now? · Cyclone preparation
- Wildfire: US wildfires now · Wildfire smoke: what protects you
- Coastal flooding: Flood safety: why shallow water kills · Hurricanes and storms now
- Your property's flood zone: FEMA Flood Map Service Center ↗ — this page cannot tell you that.
- Official preparedness guidance: Ready.gov ↗ and your county emergency management office.
What this page shows, and what it misses
FEMA's National Risk Index rates a whole county against every other US county; it is a planning-level estimate for nationwide comparison, not a flood-zone map and not a substitute for a local risk assessment or the risk to one home. Declarations are presidential disaster, emergency and fire management declarations that named this county; state declarations and SBA or USDA designations are not included. Tornadoes are counted when the county is one of up to four listed on the track; 670 tornadoes that crossed a state line carry no county list in NOAA's file and are left out.
Federal Emergency Management Agency (FEMA), National Risk Index Dataset: National Risk Index Counties - v1.20.0 (December 2025). Retrieved from https://services.arcgis.com/XG15cJAlne2vxtgt/ArcGIS/rest/services/National_Risk_Index_Counties/FeatureServer/0/query on November 2, 2026, 1:20 PM EST. This product uses the Federal Emergency Management Agency’s National Risk Index dataset API or downloadable datasets but is not endorsed by FEMA. The Federal Government or FEMA cannot vouch for the data or analyses derived from these data after the data have been retrieved from the Agency's website(s).
Federal Emergency Management Agency (FEMA), OpenFEMA Dataset: Disaster Declarations Summaries - v2, retrieved from https://www.fema.gov/api/open/v2/DisasterDeclarationsSummaries on November 2, 2026, 1:21 PM EST. This product uses the Federal Emergency Management Agency's OpenFEMA API, but is not endorsed by FEMA. The Federal Government or FEMA cannot vouch for the data or analyses derived from these data after the data have been retrieved from the Agency's website(s).
Tornado records: NOAA/NWS Storm Prediction Center, Severe Weather Database, tornadoes 1950–2025 (https://www.spc.noaa.gov/wcm/data/1950-2025_actual_tornadoes.csv, downloaded 2 November 2026). Public domain; not endorsed by NOAA. Compiled by Global Incident Tracker.
Questions about Nassau County
What natural disasters is Nassau County, Florida most at risk from?
Nassau County, Florida has a Relatively Low natural-hazard risk rating in FEMA's National Risk Index (v1.20, December 2025): a score of 59.3 out of 100, higher than about 59% of US counties, with hurricanes, wildfires and coastal flooding scoring highest of its 18 hazards and $25 million a year in expected losses.
How many federal disaster declarations has Nassau County had?
OpenFEMA lists 38 federal disaster declarations that included Nassau County since 1973, not counting 2 for COVID-19; the latest is DR-4834-FL (Hurricane Milton, declared 11 October 2024). Another 31 Florida declarations were made statewide without a county list.
How many tornadoes have hit Nassau County?
NOAA's Storm Prediction Center recorded 32 tornadoes touching Nassau County from 1950 to 2025. The deadliest: 25 Feb 1992, F1, 0.5 mi path, 0 killed, 4 injured (deaths and injuries are for the whole path).
Is the National Risk Index a flood zone map?
No. The National Risk Index is a planning-level estimate for a whole county, built for nationwide comparison. It does not tell you the flood zone or the risk of a single property: for that, look up the address on FEMA's Flood Map Service Center (msc.fema.gov) and ask your local floodplain manager.