Knox County, Tennessee Natural Disaster Risk
FEMA National Risk Index assessment · TN
MediumComposite Risk Score
National percentile: 92th
Knox County faces medium composite natural disaster risk (NRI Risk Index score 92.1, 92th national percentile), driven primarily by lightning and earthquake exposure. Expected annual loss across all 18 hazard types is $131M.
Source: FEMA National Risk Index v1.20 · Updated December 2025
Risk Overview
Overall natural disaster risk in Knox County is medium, with a National Risk Index score of 92.1 out of 100 — placing it in the 92nd 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.
Risk here concentrates in lightning (electrical discharges from storms that ignite fires and cause casualties) at Very High risk — $4M in expected annual loss and about 54.23 events per year; earthquake (ground shaking from sudden movement along geologic faults) at Medium risk — $30M in expected annual loss and about 0.00 events per year; and tornado (violently rotating columns of air capable of catastrophic local damage) at High risk — $20M in expected annual loss and about 0.16 events per year. Across all hazards, FEMA estimates $131M in expected annual loss for a population of 479K.
Beyond physical exposure, Knox 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 county's disaster history tells the same story: Knox County has received 19 federal disaster declarations since 1973, including 8 for severe storm events and 3 for winter storm events. The most recent was Severe Winter Storm (winter storm), declared in February 2026.
Among 95 Tennessee counties, Knox County ranks #4 for overall natural disaster risk.
Top Hazards
All 18 Hazard Risks
| Lightning | Very High | 54.23 / yr | $4M |
| Earthquake | Medium | 0.00 / yr | $30M |
| Tornado | High | 0.16 / yr | $20M |
| Landslide | Medium | 1.71 / yr | $244K |
| Winter Weather | High | 4.37 / yr | $839K |
| Riverine Flood | Medium | 2.18 / yr | $61M |
| Cold Wave | High | 0.53 / yr | $10M |
| Ice Storm | High | 0.37 / yr | $1M |
| Strong Wind | High | 4.90 / yr | $2M |
| Heat Wave | Low | 0.84 / yr | $1M |
| Hurricane | Low | 0.02 / yr | $430K |
| Wildfire | Very Low | 0.00 / yr | $118K |
| Hail | Low | 2.91 / yr | $431K |
| Drought | Low | 16.46 / yr | $71K |
| 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
Knox County has received 19 federal disaster declarations since 1973, most recently Severe Winter Storm in February 2026. Most frequent causes: Severe Storm (8), Winter Storm (3), Biological (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 |
| September 2023 | Severe Storm | Severe Storms, Straight-Line Winds, and Tornado |
| March 2023 | Winter Storm | Severe Winter Storm |
| April 2020 | Biological | Covid-19 Pandemic |
| March 2020 | Biological | Covid-19 |
| April 2019 | Flood | Severe Storms, Flooding, Landslides, and Mudslides |
| June 2017 | Severe Storm | Severe Storms, Straight-Line Winds, and Flooding |
| April 2015 | Severe Ice Storm | Severe Winter Storm and Flooding |
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 Knox County?
Knox County has a composite FEMA National Risk Index score of 92.1 out of 100, placing it in the Medium category and the 92th national percentile. This combines Expected Annual Loss, Social Vulnerability, and Community Resilience across 18 hazard types.
What are the top natural hazards in Knox County?
The three highest-rated hazards are Lightning (Very High, $4M EAL), Earthquake (Medium, $30M EAL), Tornado (High, $20M EAL). These account for most of the county's expected annual losses.
How does Knox County compare to other Tennessee counties?
Knox County ranks #4 of 95 Tennessee counties for overall natural disaster risk, with a medium rating.
How many federally declared disasters has Knox County had?
FEMA records 19 federal disaster declarations for Knox County since 1973, most often 8 for severe storm events and 3 for winter storm 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. Knox County's $131M EAL is a statistical average, not a guarantee for any specific year or address.