Decatur County, Tennessee Natural Disaster Risk
FEMA National Risk Index assessment · TN
Very LowComposite Risk Score
National percentile: 38th
Decatur County faces very low composite natural disaster risk (NRI Risk Index score 38.4, 38th national percentile), driven primarily by earthquake and cold wave exposure. Expected annual loss across all 18 hazard types is $8M.
Source: FEMA National Risk Index v1.20 · Updated December 2025
Risk Overview
Overall natural disaster risk in Decatur County is very low, with a National Risk Index score of 38.4 out of 100 — placing it in the 38th national percentile and among the lowest-risk counties in the country. The score blends Expected Annual Loss, Social Vulnerability, and Community Resilience across all 18 FEMA hazard types.
Risk here concentrates in earthquake (ground shaking from sudden movement along geologic faults) at Low risk — $2M in expected annual loss and about 0.01 events per year; cold wave (prolonged spells of dangerously low temperatures) at Medium risk — $2M in expected annual loss and about 1.68 events per year; and tornado (violently rotating columns of air capable of catastrophic local damage) at Medium risk — $2M in expected annual loss and about 0.24 events per year. Across all hazards, FEMA estimates $8M in expected annual loss for a population of 11K.
Beyond physical exposure, Decatur County has a very high 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). That combination — a more vulnerable population with limited resilience — can amplify the human cost of any given event.
History supports the rating: Decatur County has received 28 federal disaster declarations since 1974, including 16 for severe storm events and 5 for tornado events. The most recent was Severe Winter Storm (winter storm), declared in February 2026.
Among 95 Tennessee counties, Decatur County ranks #68 for overall natural disaster risk.
Top Hazards
All 18 Hazard Risks
| Earthquake | Low | 0.01 / yr | $2M |
| Cold Wave | Medium | 1.68 / yr | $2M |
| Tornado | Medium | 0.24 / yr | $2M |
| Heat Wave | Low | 12.26 / yr | $298K |
| Strong Wind | Low | 3.34 / yr | $370K |
| Hurricane | Very Low | 0.03 / yr | $39K |
| Landslide | Very Low | 0.90 / yr | $788 |
| Lightning | Low | 58.65 / yr | $104K |
| Riverine Flood | Very Low | 1.50 / yr | $3M |
| Drought | Very Low | 9.09 / yr | $16K |
| Ice Storm | Very Low | 0.67 / yr | $16K |
| Wildfire | Very Low | 0.00 / yr | $3K |
| Winter Weather | Very Low | 5.95 / yr | $7K |
| Hail | Very Low | 3.13 / yr | $13K |
| Avalanche | Very Low | 0.00 / yr | $0 |
| Coastal Flood | Very Low | 0.00 / yr | $0 |
| Tsunami | Very Low | 0.00 / yr | $0 |
| Volcanic Activity | Very Low | 0.00 / yr | $0 |
Disaster History
Decatur County has received 28 federal disaster declarations since 1974, most recently Severe Winter Storm in February 2026. Most frequent causes: Severe Storm (16), Tornado (5), Winter Storm (2).
| Declared | Type | Disaster |
|---|---|---|
| February 2026 | Winter Storm | Severe Winter Storm |
| January 2026 | Winter Storm | Severe Winter Storm |
| June 2025 | Severe Storm | Severe Storms, Straight-Line Winds, Tornadoes, and Flooding |
| April 2025 | Severe Storm | Severe Storms, Straight-Line Winds, Tornadoes, and Flooding |
| May 2023 | Severe Storm | Severe Storms, Straight-Line Winds, and Tornado |
| January 2022 | Tornado | Severe Storms, Straight-Line Winds, and Tornadoes |
| December 2021 | Tornado | Severe Storms, Straight-Line Winds, and Tornadoes |
| May 2021 | Tornado | Severe Storms, Tornadoes, and Flooding |
| July 2020 | Severe Storm | Severe Storms, Straight-Line Winds, and Flooding |
| April 2020 | Biological | Covid-19 Pandemic |
Showing the 10 most recent of 28 declarations.
Source: FEMA Disaster Declarations Summaries (OpenFEMA).
Frequently Asked Questions
What is the overall natural disaster risk for Decatur County?
Decatur County has a composite FEMA National Risk Index score of 38.4 out of 100, placing it in the Very Low category and the 38th national percentile. This combines Expected Annual Loss, Social Vulnerability, and Community Resilience across 18 hazard types.
What are the top natural hazards in Decatur County?
The three highest-rated hazards are Earthquake (Low, $2M EAL), Cold Wave (Medium, $2M EAL), Tornado (Medium, $2M EAL). These account for most of the county's expected annual losses.
How does Decatur County compare to other Tennessee counties?
Decatur County ranks #68 of 95 Tennessee counties for overall natural disaster risk, with a very low rating.
How many federally declared disasters has Decatur County had?
FEMA records 28 federal disaster declarations for Decatur County since 1974, most often 16 for severe storm events and 5 for tornado events. The most recent was Severe Winter Storm, declared in February 2026.
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. Decatur County's $8M EAL is a statistical average, not a guarantee for any specific year or address.