Chatham County, Georgia Natural Disaster Risk
FEMA National Risk Index assessment · GA
HighComposite Risk Score
National percentile: 97th
Chatham County faces high composite natural disaster risk (NRI Risk Index score 97.4, 97th national percentile), driven primarily by hurricane and coastal flood exposure. Expected annual loss across all 18 hazard types is $277M.
Source: FEMA National Risk Index v1.20 · Updated December 2025
Risk Overview
FEMA's National Risk Index rates Chatham County at high composite risk, with a National Risk Index score of 97.4 out of 100 — placing it in the 97th 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 hurricane (tropical cyclones bringing extreme wind, rain, and storm surge) at Very High risk — $189M in expected annual loss and about 0.35 events per year; coastal flood (seawater inundation from storm surge, high tides, and rising sea levels) at Very High risk — $13M in expected annual loss and about 3.67 events per year; and lightning (electrical discharges from storms that ignite fires and cause casualties) at High risk — $2M in expected annual loss and about 64.88 events per year. Across all hazards, FEMA estimates $277M in expected annual loss for a population of 294K.
Beyond physical exposure, Chatham County has a medium social vulnerability rating (how susceptible the population is to harm) and a very 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: Chatham County has received 19 federal disaster declarations since 1977, including 9 for hurricane events and 3 for tropical storm events. The most recent was Hurricane Helene (hurricane), declared in September 2024.
Among 159 Georgia counties, Chatham County ranks #1 for overall natural disaster risk.
Top Hazards
All 18 Hazard Risks
| Hurricane | Very High | 0.35 / yr | $189M |
| Coastal Flood | Very High | 3.67 / yr | $13M |
| Lightning | High | 64.88 / yr | $2M |
| Heat Wave | Medium | 9.53 / yr | $6M |
| Earthquake | Medium | 0.00 / yr | $12M |
| Wildfire | Medium | 0.00 / yr | $2M |
| Riverine Flood | Medium | 1.29 / yr | $42M |
| Ice Storm | High | 0.48 / yr | $891K |
| Strong Wind | Medium | 1.12 / yr | $1M |
| Cold Wave | Medium | 0.61 / yr | $4M |
| Tornado | Medium | 0.19 / yr | $3M |
| Hail | Low | 1.71 / yr | $532K |
| Winter Weather | Medium | 0.61 / yr | $120K |
| Drought | Low | 18.34 / yr | $54K |
| Landslide | Very Low | 0.07 / yr | $102 |
| Avalanche | Very Low | 0.00 / yr | $0 |
| Tsunami | Very Low | 0.00 / yr | $0 |
| Volcanic Activity | Very Low | 0.00 / yr | $0 |
Disaster History
Chatham County has received 19 federal disaster declarations since 1977, most recently Hurricane Helene in September 2024. Most frequent causes: Hurricane (9), Tropical Storm (3), Biological (2).
| Declared | Type | Disaster |
|---|---|---|
| September 2024 | Hurricane | Hurricane Helene |
| September 2024 | Tropical Storm | Hurricane Helene |
| September 2024 | Tropical Storm | Tropical Storm Debby |
| August 2024 | Tropical Storm | Hurricane Debby |
| March 2020 | Biological | Covid-19 Pandemic |
| March 2020 | Biological | Covid-19 |
| September 2019 | Hurricane | Hurricane Dorian |
| October 2018 | Hurricane | Hurricane Michael |
| September 2017 | Hurricane | Hurricane Irma |
| September 2017 | Hurricane | Hurricane Irma |
Showing the 10 most recent of 19 declarations.
Source: FEMA Disaster Declarations Summaries (OpenFEMA).
Frequently Asked Questions
What is the overall natural disaster risk for Chatham County?
Chatham County has a composite FEMA National Risk Index score of 97.4 out of 100, placing it in the High category and the 97th national percentile. This combines Expected Annual Loss, Social Vulnerability, and Community Resilience across 18 hazard types.
What are the top natural hazards in Chatham County?
The three highest-rated hazards are Hurricane (Very High, $189M EAL), Coastal Flood (Very High, $13M EAL), Lightning (High, $2M EAL). These account for most of the county's expected annual losses.
How does Chatham County compare to other Georgia counties?
Chatham County ranks #1 of 159 Georgia counties for overall natural disaster risk, with a high rating.
How many federally declared disasters has Chatham County had?
FEMA records 19 federal disaster declarations for Chatham County since 1977, most often 9 for hurricane events and 3 for tropical storm events. The most recent was Hurricane Helene, declared in September 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. Chatham County's $277M EAL is a statistical average, not a guarantee for any specific year or address.