Seminole County, Florida Natural Disaster Risk
FEMA National Risk Index assessment · FL
MediumComposite Risk Score
National percentile: 91th
Seminole County faces medium composite natural disaster risk (NRI Risk Index score 91.4, 91th national percentile), driven primarily by tornado and strong wind exposure. Expected annual loss across all 18 hazard types is $129M.
Source: FEMA National Risk Index v1.20 · Updated December 2025
Risk Overview
Seminole County carries a medium composite natural disaster risk, with a National Risk Index score of 91.4 out of 100 — placing it in the 91st national percentile and near the national midpoint for natural-disaster risk. The score blends Expected Annual Loss, Social Vulnerability, and Community Resilience across all 18 FEMA hazard types.
Most of Seminole County's expected losses come from tornado (violently rotating columns of air capable of catastrophic local damage) at High risk — $26M in expected annual loss and about 0.23 events per year; strong wind (damaging straight-line winds outside of tornadoes and hurricanes) at High risk — $5M in expected annual loss and about 1.07 events per year; and lightning (electrical discharges from storms that ignite fires and cause casualties) at High risk — $3M in expected annual loss and about 87.16 events per year. Across all hazards, FEMA estimates $129M in expected annual loss for a population of 471K.
Beyond physical exposure, Seminole County has a very low social vulnerability rating (how susceptible the population is to harm) and a medium community resilience rating (its capacity to prepare for and recover from disasters). Both measures sit toward the lower end, indicating relatively modest population sensitivity.
The federal record bears this out: Seminole County has received 39 federal disaster declarations since 1977, including 20 for hurricane events and 5 for freezing events. The most recent was Hurricane Milton (hurricane), declared in October 2024.
Among 67 Florida counties, Seminole County ranks #29 for overall natural disaster risk.
Top Hazards
All 18 Hazard Risks
| Tornado | High | 0.23 / yr | $26M |
| Strong Wind | High | 1.07 / yr | $5M |
| Lightning | High | 87.16 / yr | $3M |
| Hurricane | High | 0.25 / yr | $25M |
| Riverine Flood | Medium | 0.46 / yr | $66M |
| Wildfire | Medium | 0.01 / yr | $2M |
| Heat Wave | Low | 1.90 / yr | $2M |
| Earthquake | Low | 0.00 / yr | $786K |
| Cold Wave | Low | 3.90 / yr | $484K |
| Hail | Very Low | 2.06 / yr | $96K |
| Landslide | Very Low | 0.03 / yr | $140 |
| Drought | Very Low | 13.59 / yr | $3K |
| Avalanche | Very Low | 0.00 / yr | $0 |
| Coastal Flood | Very Low | 0.01 / yr | $0 |
| Ice Storm | Very Low | 0.00 / yr | $0 |
| Tsunami | Very Low | 0.00 / yr | $0 |
| Volcanic Activity | Very Low | 0.00 / yr | $0 |
| Winter Weather | Very Low | 0.00 / yr | $0 |
Disaster History
Seminole County has received 39 federal disaster declarations since 1977, most recently Hurricane Milton in October 2024. Most frequent causes: Hurricane (20), Freezing (5), Tropical Storm (4).
| Declared | Type | Disaster |
|---|---|---|
| October 2024 | Hurricane | Hurricane Milton |
| October 2024 | Hurricane | Hurricane Milton |
| 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 |
| September 2022 | Hurricane | Tropical Storm Ian |
Showing the 10 most recent of 39 declarations.
Source: FEMA Disaster Declarations Summaries (OpenFEMA).
Frequently Asked Questions
What is the overall natural disaster risk for Seminole County?
Seminole County has a composite FEMA National Risk Index score of 91.4 out of 100, placing it in the Medium category and the 91th national percentile. This combines Expected Annual Loss, Social Vulnerability, and Community Resilience across 18 hazard types.
What are the top natural hazards in Seminole County?
The three highest-rated hazards are Tornado (High, $26M EAL), Strong Wind (High, $5M EAL), Lightning (High, $3M EAL). These account for most of the county's expected annual losses.
How does Seminole County compare to other Florida counties?
Seminole County ranks #29 of 67 Florida counties for overall natural disaster risk, with a medium rating.
How many federally declared disasters has Seminole County had?
FEMA records 39 federal disaster declarations for Seminole County since 1977, most often 20 for hurricane events and 5 for freezing 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. Seminole County's $129M EAL is a statistical average, not a guarantee for any specific year or address.