Lewis County, Tennessee Natural Disaster Risk
FEMA National Risk Index assessment · TN
Very LowComposite Risk Score
National percentile: 14th
Lewis County faces very low composite natural disaster risk (NRI Risk Index score 13.9, 14th national percentile), driven primarily by earthquake and tornado exposure. Expected annual loss across all 18 hazard types is $5M.
Source: FEMA National Risk Index v1.20 · Updated December 2025
Risk Overview
FEMA's National Risk Index rates Lewis County at very low composite risk, with a National Risk Index score of 13.9 out of 100 — placing it in the 14th 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.
Most of Lewis County's expected losses come from earthquake (ground shaking from sudden movement along geologic faults) at Low risk — $815K in expected annual loss and about 0.00 events per year; tornado (violently rotating columns of air capable of catastrophic local damage) at Low risk — $2M in expected annual loss and about 0.23 events per year; and landslide (downhill movement of rock, soil, and debris on unstable slopes) at Very Low risk — $2K in expected annual loss and about 0.92 events per year. Across all hazards, FEMA estimates $5M in expected annual loss for a population of 12K.
Beyond physical exposure, Lewis County has a medium social vulnerability rating (how susceptible the population is to harm) and a very 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.
The federal record bears this out: Lewis County has received 24 federal disaster declarations since 1975, including 16 for severe storm events and 3 for flood events. The most recent was Severe Winter Storm (winter storm), declared in February 2026.
Among 95 Tennessee counties, Lewis County ranks #85 for overall natural disaster risk.
Top Hazards
All 18 Hazard Risks
| Earthquake | Low | 0.00 / yr | $815K |
| Tornado | Low | 0.23 / yr | $2M |
| Landslide | Very Low | 0.92 / yr | $2K |
| Cold Wave | Low | 1.21 / yr | $796K |
| Hurricane | Very Low | 0.03 / yr | $23K |
| Strong Wind | Low | 5.30 / yr | $337K |
| Ice Storm | Low | 0.73 / yr | $35K |
| Lightning | Low | 60.42 / yr | $96K |
| Heat Wave | Very Low | 5.63 / yr | $107K |
| Winter Weather | Low | 4.74 / yr | $22K |
| Drought | Very Low | 13.82 / yr | $5K |
| Riverine Flood | Very Low | 0.75 / yr | $2M |
| Wildfire | Very Low | 0.00 / yr | $3K |
| Hail | Very Low | 3.65 / yr | $23K |
| 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
Lewis County has received 24 federal disaster declarations since 1975, most recently Severe Winter Storm in February 2026. Most frequent causes: Severe Storm (16), Flood (3), 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 |
| April 2023 | Severe Storm | Severe Storms, Straight-Line Winds, and Tornadoes |
| July 2020 | Severe Storm | Severe Storms, 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 |
Showing the 10 most recent of 24 declarations.
Source: FEMA Disaster Declarations Summaries (OpenFEMA).
Frequently Asked Questions
What is the overall natural disaster risk for Lewis County?
Lewis County has a composite FEMA National Risk Index score of 13.9 out of 100, placing it in the Very Low category and the 14th national percentile. This combines Expected Annual Loss, Social Vulnerability, and Community Resilience across 18 hazard types.
What are the top natural hazards in Lewis County?
The three highest-rated hazards are Earthquake (Low, $815K EAL), Tornado (Low, $2M EAL), Landslide (Very Low, $2K EAL). These account for most of the county's expected annual losses.
How does Lewis County compare to other Tennessee counties?
Lewis County ranks #85 of 95 Tennessee counties for overall natural disaster risk, with a very low rating.
How many federally declared disasters has Lewis County had?
FEMA records 24 federal disaster declarations for Lewis County since 1975, most often 16 for severe storm events and 3 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. Lewis County's $5M EAL is a statistical average, not a guarantee for any specific year or address.