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Williamson County, Tennessee

Natural disaster risk, federal disaster history and flood insurance facts.

Relatively Moderate overall risk
11th of 95highest risk in Tennessee
$98Mexpected losses a year
14federal declarations
1 in 42homes with flood insurance
Photo: U.S. Geological Survey, public domain

Williamson County, Tennessee has a moderate overall risk from natural hazards in FEMA's National Risk Index. Its risk score is higher than 85% of US counties. It ranks 11th of 95 counties in Tennessee. The costliest hazards here are inland flooding, cold waves and tornadoes. FEMA estimates about $98 million a year in expected losses, or roughly $396 per resident. Since 1974 it has been included in 14 federal disaster or emergency declarations for natural events (11 major disasters). The most recent was in February 2026 (severe winter storm). About 1 in 42 homes here carry federal flood insurance (1,284 policies). Since 1978, federal flood insurance has paid about $31 million on 1,103 claims here, including $18 million for floods in 2010.

FEMA National Risk Index December 2025; OpenFEMA declarations to Nov 6, 2026; NFIP records. Updated November 6, 2026.

Top risks in Williamson County

$57 million a yearExpected losses. Damaging events about 2 times a year.
  • Check the FEMA flood map for your address, and ask the seller or landlord about past flooding.
  • Price a flood policy now. Most new federal policies take 30 days to start.
$13.4 million a yearExpected losses. Damaging events about once a year.
  • Insulate pipes in outside walls, crawl spaces and garages.
  • Know how to shut off the main water valve.

Tornado

Moderate
$11.6 million a yearExpected losses. Damaging events about once every 2 years.
  • Pick a shelter spot: a basement, or an inside room on the lowest floor with no windows.
  • Turn on emergency alerts on your phone and keep a weather radio.
HazardRatingScoreExpected loss a year
Inland floodingModerate88.2
$57M
Cold waveHigh90.7
$13M
TornadoModerate88.9
$12M
EarthquakeLow89.4
$8M
Strong windHigh89.1
$3M
Heat waveLow72.5
$2M
Ice stormHigh84.4
$1M
Winter weatherModerate84.7
$469K
LightningLow53.7
$468K
HailLow41.9
$332K
DroughtLow35.8
$77K
HurricaneVery Low41.0
$55K
WildfireVery Low39.8
$45K
LandslideVery Low54.2
$3K

Scores are percentiles: a score of 90 means higher risk than about 90% of US counties for that hazard. Hazards FEMA does not rate here are left out. Social vulnerability is very low and community resilience is very high in FEMA's measures.

Federal disaster history

Recent disasters nationwide ›

Declarations by decade

Federal declarations for natural events that included Williamson County. 2020s bar runs to November 2026.

By type

Severe Storm8
Tornado2
Winter Storm2
Flood1
Hurricane1

Most recent

Feb 6, 2026Severe Winter StormMajor disaster
Jan 24, 2026Severe Winter StormEmergency
Apr 2, 2025Severe Storms, Straight-Line Winds, Tornadoes, and FloodingEmergency
May 8, 2021Severe Storms, Tornadoes, and FloodingMajor disaster
May 4, 2010Severe Storms, Flooding, Straight-Line Winds, and TornadoesMajor disaster
Feb 7, 2008Severe Storms, Tornadoes, Straight-Line Winds, and FloodingMajor disaster
Sep 5, 2005Hurricane Katrina EvacuationEmergency
May 8, 2003Severe Storms, Tornadoes, and FloodingMajor disaster
May 12, 1999Severe Storms, Tornadoes and FloodingMajor disaster
Apr 20, 1998Severe Storms, Tornadoes and FloodingMajor disaster
Show all 14
Feb 28, 1994Severe Winter Ice Storm,Flash FloodingMajor disaster
May 7, 1979Severe Storms, Tornadoes & FloodingMajor disaster
Mar 22, 1975Severe Storms & FloodingMajor disaster
Apr 4, 1974TornadoesMajor disaster

Tennessee also had 1 statewide declarations that did not name single counties.

Storm history since 1960

Tornado risk by county ›

The National Weather Service has logged 795 storm reports in Williamson County since 1960, with 8 deaths and 23 injuries and about $57.8 million in reported damage. The strongest on record here was an F4 tornado on December 24, 1988.

26tornadoes
197hail reports, largest 3 inches
435damaging thunderstorm winds
101floods and flash floods

Strongest tornadoes

DateStrengthNearHurt / killed
Dec 24, 1988F4–7 / 1
May 11, 2003F3Franklin1 / 0
Jan 10, 1963F3–0 / 0
Feb 5, 2008EF2Lampley Store0 / 0
Mar 1, 2017EF1Berrys Chapel0 / 0

Most damaging storms

DateTypeNearDamage
Dec 24, 1988Tornado–$25M
May 2, 2010FloodNolensville$10M
Mar 1, 2017TornadoBerrys Chapel$7M
May 5, 2003TornadoFranklin$3M
May 11, 2003TornadoFranklin$2M
Oct 24, 2010LightningMallorys$2M

Source: NOAA Storm Events Database, county-based reports through Jul 21, 2026. Tornado records start in 1950, hail and wind in 1955, and floods and other storm types in 1996, so older decades undercount. Damage is in dollars of the year it happened and is often an estimate. Winter storms, heat and hurricanes are logged by forecast zone, not county, so they are not counted here.

Hurricanes and tropical storms

Hurricane risk by county ›

Since 1888, 0 hurricanes and 5 tropical storms have passed within 65 miles of the center of Williamson County, 2 of them since 1950. The strongest was an unnamed storm in 1888, with top winds near 55 mph about 64 miles away.

0hurricanes
0major hurricanes (Category 3+)
5tropical storms
1979most recent: Frederic

Strongest storms nearby

DateStormStrengthClosest
Aug 21, 1888UnnamedTropical storm, 55 mph64 mi
Sep 13, 1979FredericTropical storm, 45 mph64 mi
Sep 13, 1892UnnamedTropical storm, 45 mph55 mi
Jun 28, 1957AudreyTropical storm, 40 mph42 mi
Jun 18, 1934UnnamedTropical storm, 40 mph47 mi

Most recent storms

DateStormStrengthClosest
Sep 13, 1979FredericTropical storm, 45 mph64 mi
Jun 28, 1957AudreyTropical storm, 40 mph42 mi
Jun 18, 1934UnnamedTropical storm, 40 mph47 mi
Sep 13, 1892UnnamedTropical storm, 45 mph55 mi
Aug 21, 1888UnnamedTropical storm, 55 mph64 mi

Source: NOAA National Hurricane Center best-track records (HURDAT2), 1851 to 2025 for the Atlantic and 1949 to 2025 for the eastern Pacific. A storm counts if its track passed within 65 miles of the county's center while it was a tropical storm or hurricane. Strength is the storm's top sustained wind at that point, not the wind measured in the county. Older storms over the open sea were sometimes missed.

Flood insurance in Williamson County

Check your address flood zone ›
2.4%of homes have federal flood insurance (1,284 policies)
86.3%of homes in mapped high-risk flood zones are insured
$30.8 millionpaid on 1,103 flood claims since 1978
2010costliest year, with $18.2 million paid

National Flood Insurance Program (NFIP) records only; private flood policies are not included. Home counts as of Aug 3, 2026. Since 2021 NFIP prices each home separately under Risk Rating 2.0, so your price depends on the building, not the county. Ask an agent for a quote.

Homes in Williamson County

$751,900median home value (Tennessee $286,700, US $332,700)
2002median year homes were built (Tennessee 1987, US 1980)
16%of homes built before 1980, before many modern wind, quake and flood building rules
1.5%of homes are mobile homes, which are the least safe in tornadoes and high winds

Older homes and mobile homes usually suffer more damage in storms, floods and earthquakes, and can cost more to insure. If you are buying, ask about roof age, foundation bolting and any retrofits. Source: US Census Bureau, American Community Survey 2020 to 2024 5-year estimates; 96,921 housing units.

Compare in Tennessee

All 95 ›
Largest countiesOverall riskTop hazard
Shelby CountyHighEarthquake
Davidson CountyHighInland flooding
Knox CountyModerateInland flooding
Hamilton CountyModerateInland flooding
Rutherford CountyModerateInland flooding
Williamson CountyModerateInland flooding
Montgomery CountyModerateInland flooding
Sumner CountyModerateInland flooding

Neighboring counties

CountyOverall riskDeclarations
Davidson CountyHigh25
Rutherford CountyModerate15
Maury CountyLow19
Dickson CountyLow25
Cheatham CountyLow23
Marshall CountyLow15
Hickman CountyLow23

Common questions about Williamson County

What is the biggest natural hazard in Williamson County?

Inland flooding has the highest expected yearly losses in Williamson County, about $57 million a year in FEMA's estimate. Cold wave is second at $13.4 million.

How many federal disasters has Williamson County had?

Williamson County has been included in 14 federal disaster or emergency declarations for natural events since 1974, including 11 major disasters. The most recent was Severe Winter Storm in February 2026.

Is Williamson County a high-risk place to live?

Its overall rating is Relatively Moderate, 11th highest of 95 in Tennessee. A county rating covers the whole area. Risk at one address can be much higher or lower, so check the FEMA flood map and ask about the home's history.

Do I need flood insurance in Williamson County?

Standard home insurance does not cover flooding. About 1 in 42 homes in Williamson County has federal flood insurance. Lenders require it in mapped high-risk zones, but many flood claims come from outside those zones.

How many tornadoes has Williamson County had?

NOAA records list 26 tornadoes in Williamson County since 1950. The strongest was an F4 tornado on December 24, 1988. The weather service has also logged 197 hail reports and 101 floods here.

How many hurricanes have hit Williamson County?

NOAA's hurricane records show 0 hurricanes and 5 tropical storms passing within 65 miles of the center of Williamson County. The strongest was an unnamed storm in 1888, with winds near 55 mph.

Sources: FEMA National Risk Index (December 2025), OpenFEMA Disaster Declarations Summaries, and NFIP policy and claims data. Hazard Compass is independent and not affiliated with FEMA. These figures describe the whole county, not a single property, and are not insurance or safety advice. Report a problem.