Knox County, Tennessee: Natural Disaster Risk and History
Knox County, Tennessee has a Relatively Moderate natural-hazard risk rating in FEMA's National Risk Index (v1.20, December 2025): a score of 92.1 out of 100, higher than about 92% of US counties, with lightning, earthquakes and tornadoes scoring highest of its 18 hazards and $131 million a year in expected losses.
OpenFEMA lists 17 federal disaster declarations that included Knox County since 1973, not counting 2 for COVID-19; the latest is DR-4898-TN (Severe Winter Storm, declared 6 February 2026). NOAA's Storm Prediction Center recorded 17 tornadoes touching Knox County from 1950 to 2025.
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Population 478,842 Buildings worth $92 billion Area 531 sq mi Risk rank in Tennessee 4 of 95 FIPS 47093
All 18 hazards, highest risk first
FEMA National Risk Index| Hazard | Risk rating | Score | Expected loss a year | How often | Events in record |
|---|---|---|---|---|---|
| Lightning | Very High | 98.1 | $3.6 million | about 54 a year | 416,649 strikes |
| Earthquake | Relatively Moderate | 96.8 | $30 million | about once every 216 years | — |
| Tornado | Relatively High | 96.7 | $20 million | about once every 6.3 years | 15 |
| Landslide | Relatively Moderate | 96.5 | $243,645 | about 1.7 a year | — |
| Winter weather | Relatively High | 95.4 | $838,744 | about 4.4 a year | 83 |
| Inland flooding | Relatively Moderate | 92.8 | $61 million | about 2.2 a year | 61 |
| Cold wave | Relatively High | 92.6 | $9.9 million | about once every 1.9 years | 10 |
| Ice storm | Relatively High | 92.3 | $1.3 million | about once every 2.7 years | 26 |
| Strong wind | Relatively High | 89.3 | $2.2 million | about 4.9 a year | 187 |
| Heat wave | Relatively Low | 72.6 | $1.2 million | about once every 1.2 years | 15 |
| Hurricane | Relatively Low | 65.8 | $429,879 | about once every 62 years | 3 |
| Wildfire | Very Low | 63.0 | $118,379 | about once every 658 years | — |
| Hail | Relatively Low | 59.7 | $430,505 | about 2.9 a year | 111 |
| Drought | Relatively Low | 39.4 | $70,906 | about 17 a year | 574 |
| Avalanche | Not Applicable | — | — | — | — |
| Coastal flooding | Not Applicable | — | — | — | — |
| Tsunami | Not Applicable | — | — | — | — |
| Volcanic activity | Not Applicable | — | — | — | — |
Score: FEMA's percentile among US counties that face the hazard (higher = more risk). Expected loss: FEMA's modelled average yearly loss to buildings, people (as a statistical value) and crops. How often: FEMA's annualised frequency of the hazard in the county; for some hazards it counts event-days, so it is a rough guide, not a forecast. "Not Applicable" means FEMA does not model that hazard here.
Federal disaster declarations 17
Most common: Severe Storm 8, Winter Storm 3, Flood 2, Severe Ice Storm 1.
| Decade | Declarations | Incident types |
|---|---|---|
| 1970s | 2 | Tornado, Flood |
| 1990s | 2 | Severe Storm, Snowstorm |
| 2000s | 3 | Severe Storm ×2, Hurricane |
| 2010s | 5 | Severe Storm ×3, Flood, Severe Ice Storm |
| 2020s | 5 | Winter Storm ×3, Severe Storm ×2 |
The last 10
Widest declarations that included Knox County
- Severe Winter Storm (2026, DR-4898-TN): 95 Tennessee counties designated.
- Severe Winter Storm (2026, EM-3635-TN): 95 Tennessee counties designated.
- Severe Storms, Straight-Line Winds, Tornadoes, and Flooding (2025, EM-3625-TN): 95 Tennessee counties designated.
Named storms in its declarations: Hurricane Katrina (2005).
Not counted above: 2 COVID-19 ("Biological") declarations — in 2020 every US county was included. Tennessee also had 1 statewide declaration with no county list.
Tornado record since 1950 17
| Tornadoes touching the county | 17 |
|---|---|
| Strongest-rated | (E)F3 ×1 |
| Peak month | May (6) |
| Deadliest | 3 Apr 1974, F1, 1 mi path, 2 killed, 21 injured |
| Longest path | 21 Feb 1993, F3, 16 mi path, 0 killed, 3 injured |
| Most recent | 7 Aug 2023, EF2, 3.7 mi path |
| Deaths / injuries on those paths | 2 / 32 |
| Rating | (E)F0 | (E)F1 | (E)F2 | (E)F3 | (E)F4 | (E)F5 | Unrated |
|---|---|---|---|---|---|---|---|
| Count | 7 | 6 | 3 | 1 | 0 | 0 | 0 |
| Decade | 1950s | 1960s | 1970s | 1980s | 1990s | 2000s | 2010s | 2020s |
|---|---|---|---|---|---|---|---|---|
| Count | 1 | 1 | 1 | 1 | 4 | 3 | 5 | 1 |
Deaths and injuries are for each tornado's whole path, which can run beyond this county. F-scale ratings before February 2007, Enhanced Fujita (EF) after.
How Knox County compares with its 5 nearest counties
| County | Distance | Overall risk | Score | Top hazard |
|---|---|---|---|---|
| Knox County (this page) | — | Relatively Moderate | 92.1 | Lightning |
| Anderson County | 27 km | Relatively Low | 73.2 | Landslide |
| Union County | 34 km | Very Low | 12.9 | Landslide |
| Blount County | 34 km | Relatively Low | 74.2 | Landslide |
| Sevier County | 44 km | Relatively Low | 77.4 | Landslide |
| Loudon County | 44 km | Relatively Low | 68.4 | Earthquake |
Nearest by distance between county centres. Every county in Tennessee, ranked.
Vulnerability and resilience
| Social vulnerability | Relatively Low 22.7 |
|---|---|
| Community resilience | Relatively High 61.3 |
| Community risk factor | 0.92 |
| Expected annual loss, all hazards | $131 million |
FEMA scales expected losses up where social vulnerability is high (people who may find it harder to prepare, evacuate or recover) and down where community resilience is high. A factor above 1 raises the risk score. For social vulnerability a high rating is worse; for resilience a high rating is better.
Prepare for Knox County's main hazards
- Right now: National Weather Service alerts for Tennessee · all official warnings on Global Incident Tracker.
- Lightning: Weather alerts for Tennessee
- Earthquake: Earthquakes today · Earthquake safety guide
- Tornado: Is there a tornado warning now?
- Your property's flood zone: FEMA Flood Map Service Center ↗ — this page cannot tell you that.
- Official preparedness guidance: Ready.gov ↗ and your county emergency management office.
What this page shows, and what it misses
FEMA's National Risk Index rates a whole county against every other US county; it is a planning-level estimate for nationwide comparison, not a flood-zone map and not a substitute for a local risk assessment or the risk to one home. Declarations are presidential disaster, emergency and fire management declarations that named this county; state declarations and SBA or USDA designations are not included. Tornadoes are counted when the county is one of up to four listed on the track; 670 tornadoes that crossed a state line carry no county list in NOAA's file and are left out.
Federal Emergency Management Agency (FEMA), National Risk Index Dataset: National Risk Index Counties - v1.20.0 (December 2025). Retrieved from https://services.arcgis.com/XG15cJAlne2vxtgt/ArcGIS/rest/services/National_Risk_Index_Counties/FeatureServer/0/query on November 2, 2026, 1:20 PM EST. This product uses the Federal Emergency Management Agency’s National Risk Index dataset API or downloadable datasets but is not endorsed by FEMA. The Federal Government or FEMA cannot vouch for the data or analyses derived from these data after the data have been retrieved from the Agency's website(s).
Federal Emergency Management Agency (FEMA), OpenFEMA Dataset: Disaster Declarations Summaries - v2, retrieved from https://www.fema.gov/api/open/v2/DisasterDeclarationsSummaries on November 2, 2026, 1:21 PM EST. This product uses the Federal Emergency Management Agency's OpenFEMA API, but is not endorsed by FEMA. The Federal Government or FEMA cannot vouch for the data or analyses derived from these data after the data have been retrieved from the Agency's website(s).
Tornado records: NOAA/NWS Storm Prediction Center, Severe Weather Database, tornadoes 1950–2025 (https://www.spc.noaa.gov/wcm/data/1950-2025_actual_tornadoes.csv, downloaded 2 November 2026). Public domain; not endorsed by NOAA. Compiled by Global Incident Tracker.
Questions about Knox County
What natural disasters is Knox County, Tennessee most at risk from?
Knox County, Tennessee has a Relatively Moderate natural-hazard risk rating in FEMA's National Risk Index (v1.20, December 2025): a score of 92.1 out of 100, higher than about 92% of US counties, with lightning, earthquakes and tornadoes scoring highest of its 18 hazards and $131 million a year in expected losses.
How many federal disaster declarations has Knox County had?
OpenFEMA lists 17 federal disaster declarations that included Knox County since 1973, not counting 2 for COVID-19; the latest is DR-4898-TN (Severe Winter Storm, declared 6 February 2026). Another 1 Tennessee declarations were made statewide without a county list.
How many tornadoes have hit Knox County?
NOAA's Storm Prediction Center recorded 17 tornadoes touching Knox County from 1950 to 2025. The deadliest: 3 Apr 1974, F1, 1 mi path, 2 killed, 21 injured (deaths and injuries are for the whole path).
Is the National Risk Index a flood zone map?
No. The National Risk Index is a planning-level estimate for a whole county, built for nationwide comparison. It does not tell you the flood zone or the risk of a single property: for that, look up the address on FEMA's Flood Map Service Center (msc.fema.gov) and ask your local floodplain manager.