Hamilton County, Tennessee Natural Disaster Risk
FEMA National Risk Index assessment · TN
MediumComposite Risk Score
National percentile: 93th
Hamilton County faces medium composite natural disaster risk (NRI Risk Index score 93.3, 93th national percentile), driven primarily by tornado and strong wind exposure. Expected annual loss across all 18 hazard types is $140M.
Source: FEMA National Risk Index v1.20 · Updated December 2025
Risk Overview
FEMA's National Risk Index rates Hamilton County at medium composite risk, with a National Risk Index score of 93.3 out of 100 — placing it in the 93rd 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 Hamilton County's expected losses come from tornado (violently rotating columns of air capable of catastrophic local damage) at High risk — $32M in expected annual loss and about 0.37 events per year; strong wind (damaging straight-line winds outside of tornadoes and hurricanes) at High risk — $5M in expected annual loss and about 4.65 events per year; and earthquake (ground shaking from sudden movement along geologic faults) at Medium risk — $17M in expected annual loss and about 0.00 events per year. Across all hazards, FEMA estimates $140M in expected annual loss for a population of 366K.
Beyond physical exposure, Hamilton County has a low social vulnerability rating (how susceptible the population is to harm) and a 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.
The federal record bears this out: Hamilton County has received 25 federal disaster declarations since 1973, including 11 for severe storm events and 5 for flood events. The most recent was Severe Winter Storm (winter storm), declared in February 2026.
Among 95 Tennessee counties, Hamilton County ranks #3 for overall natural disaster risk.
Top Hazards
All 18 Hazard Risks
| Tornado | High | 0.37 / yr | $32M |
| Strong Wind | High | 4.65 / yr | $5M |
| Earthquake | Medium | 0.00 / yr | $17M |
| Landslide | Medium | 1.20 / yr | $137K |
| Riverine Flood | High | 1.93 / yr | $75M |
| Lightning | High | 61.37 / yr | $2M |
| Winter Weather | High | 3.74 / yr | $594K |
| Ice Storm | High | 0.62 / yr | $652K |
| Cold Wave | Medium | 0.53 / yr | $5M |
| Hail | Medium | 3.68 / yr | $1M |
| Heat Wave | Low | 1.84 / yr | $1M |
| Wildfire | Low | 0.00 / yr | $185K |
| Hurricane | Low | 0.02 / yr | $276K |
| Drought | Low | 25.96 / yr | $50K |
| 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
Hamilton County has received 25 federal disaster declarations since 1973, most recently Severe Winter Storm in February 2026. Most frequent causes: Severe Storm (11), Flood (5), Winter Storm (2).
| Declared | Type | Disaster |
|---|---|---|
| February 2026 | Winter Storm | Severe Winter Storm |
| January 2026 | Winter Storm | Severe Winter Storm |
| April 2025 | Severe Storm | Severe Storms, Straight-Line Winds, Tornadoes, and Flooding |
| June 2024 | Severe Storm | Severe Storms, Tornadoes, and Flooding |
| May 2023 | Severe Storm | Severe Storms, Straight-Line Winds, and Tornado |
| April 2020 | Severe Storm | Severe Storms, Tornadoes, Straight-Line Winds, and Flooding |
| April 2020 | Biological | Covid-19 Pandemic |
| March 2020 | Biological | Covid-19 |
| April 2019 | Flood | Severe Storms, Flooding, Landslides, and Mudslides |
| November 2016 | Fire | Smith Mountain Fire Complex |
Showing the 10 most recent of 25 declarations.
Source: FEMA Disaster Declarations Summaries (OpenFEMA).
Frequently Asked Questions
What is the overall natural disaster risk for Hamilton County?
Hamilton County has a composite FEMA National Risk Index score of 93.3 out of 100, placing it in the Medium category and the 93th national percentile. This combines Expected Annual Loss, Social Vulnerability, and Community Resilience across 18 hazard types.
What are the top natural hazards in Hamilton County?
The three highest-rated hazards are Tornado (High, $32M EAL), Strong Wind (High, $5M EAL), Earthquake (Medium, $17M EAL). These account for most of the county's expected annual losses.
How does Hamilton County compare to other Tennessee counties?
Hamilton County ranks #3 of 95 Tennessee counties for overall natural disaster risk, with a medium rating.
How many federally declared disasters has Hamilton County had?
FEMA records 25 federal disaster declarations for Hamilton County since 1973, most often 11 for severe storm events and 5 for flood 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. Hamilton County's $140M EAL is a statistical average, not a guarantee for any specific year or address.