Hillsborough County, Florida Natural Disaster Risk
FEMA National Risk Index assessment · FL
HighComposite Risk Score
National percentile: 99th
Hillsborough County faces high composite natural disaster risk (NRI Risk Index score 98.8, 99th national percentile), driven primarily by lightning and tornado exposure. Expected annual loss across all 18 hazard types is $495M.
Source: FEMA National Risk Index v1.20 · Updated December 2025
Risk Overview
Hillsborough County carries a high composite natural disaster risk, with a National Risk Index score of 98.8 out of 100 — placing it in the 99th national percentile and in the upper tier of natural-disaster risk nationally. The score blends Expected Annual Loss, Social Vulnerability, and Community Resilience across all 18 FEMA hazard types.
Risk here concentrates in lightning (electrical discharges from storms that ignite fires and cause casualties) at Very High risk — $8M in expected annual loss and about 97.58 events per year; tornado (violently rotating columns of air capable of catastrophic local damage) at Very High risk — $77M in expected annual loss and about 1.31 events per year; and cold wave (prolonged spells of dangerously low temperatures) at Very High risk — $54M in expected annual loss and about 4.14 events per year. Across all hazards, FEMA estimates $495M in expected annual loss for a population of 1.46M.
Beyond physical exposure, Hillsborough County has a low social vulnerability rating (how susceptible the population is to harm) and a low community resilience rating (its capacity to prepare for and recover from disasters). Both measures sit toward the lower end, indicating relatively modest population sensitivity.
History supports the rating: Hillsborough County has received 47 federal disaster declarations since 1968, including 21 for hurricane events and 7 for severe storm events. The most recent was Hurricane Milton (hurricane), declared in October 2024.
Among 67 Florida counties, Hillsborough County ranks #6 for overall natural disaster risk.
Top Hazards
All 18 Hazard Risks
| Lightning | Very High | 97.58 / yr | $8M |
| Tornado | Very High | 1.31 / yr | $77M |
| Cold Wave | Very High | 4.14 / yr | $54M |
| Hurricane | Very High | 0.25 / yr | $178M |
| Hail | High | 1.83 / yr | $6M |
| Riverine Flood | High | 2.14 / yr | $146M |
| Heat Wave | High | 3.51 / yr | $9M |
| Wildfire | Medium | 0.01 / yr | $4M |
| Coastal Flood | High | 3.69 / yr | $8M |
| Drought | Medium | 17.15 / yr | $1M |
| Strong Wind | Medium | 0.87 / yr | $1M |
| Earthquake | Low | 0.00 / yr | $735K |
| Landslide | Low | 0.13 / yr | $4K |
| Avalanche | Very Low | 0.00 / 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
Hillsborough County has received 47 federal disaster declarations since 1968, most recently Hurricane Milton in October 2024. Most frequent causes: Hurricane (21), Severe Storm (7), Tropical Storm (5).
| Declared | Type | Disaster |
|---|---|---|
| October 2024 | Hurricane | Hurricane Milton |
| October 2024 | Hurricane | Hurricane Milton |
| September 2024 | Hurricane | Hurricane Helene |
| September 2024 | Tropical Storm | Tropical Storm 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 |
Showing the 10 most recent of 47 declarations.
Source: FEMA Disaster Declarations Summaries (OpenFEMA).
Frequently Asked Questions
What is the overall natural disaster risk for Hillsborough County?
Hillsborough County has a composite FEMA National Risk Index score of 98.8 out of 100, placing it in the High category and the 99th national percentile. This combines Expected Annual Loss, Social Vulnerability, and Community Resilience across 18 hazard types.
What are the top natural hazards in Hillsborough County?
The three highest-rated hazards are Lightning (Very High, $8M EAL), Tornado (Very High, $77M EAL), Cold Wave (Very High, $54M EAL). These account for most of the county's expected annual losses.
How does Hillsborough County compare to other Florida counties?
Hillsborough County ranks #6 of 67 Florida counties for overall natural disaster risk, with a high rating.
How many federally declared disasters has Hillsborough County had?
FEMA records 47 federal disaster declarations for Hillsborough County since 1968, most often 21 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. Hillsborough County's $495M EAL is a statistical average, not a guarantee for any specific year or address.