Williamson County, Texas

What hazards hit Williamson County most?

The most frequent records are hail reports: 458 since 1959. 59% of its hail reports since 1959 fell in April and May. The rank column places the county among Texas's counties by days with a record per 1,000 square miles of land over each hazard's complete period.

Source: NOAA NCEI Storm Events Database (county and forecast-zone records attributed to the county; a zone record shows its own totals on each county it covers). Days: dates with at least one record of the hazard in the county. Ranks: days with a record per 1,000 square miles of land (Census Bureau 2024 Gazetteer), since 1950 for tornadoes, 1955 for hail and thunderstorm wind, 1996 for the rest.

How many tornadoes has Williamson County had?

NOAA records 71 tornadoes in Williamson County from 1954 to 2022, the strongest rated F5, with 29 deaths and 70 injuries recorded in the county. That is 65th of 254 Texas counties by days with tornadoes per 1,000 square miles since 1950. A tornado that crossed a county line is counted in each county it touched, with the length of its path inside the county.

Counted as whole tornadoes rather than county records, the Storm Prediction Center's database holds 73 tornadoes whose track touched Williamson County since 1950 (NOAA's county records number 71: they file a crossing tornado once per county segment, and the two databases differ on some tracks); along their whole tracks they killed 29 people.

Map of the strongest tornado tracks in Texas.

Source: NOAA NCEI Storm Events Database, tornado records by county (path length in the county, maximum width); ratings as published: F scale before February 1, 2007, EF scale after. Whole-track figures: NOAA Storm Prediction Center tornado database (1950-2025). SPC severe weather database.

When was the last damaging storm in Williamson County?

The most recent record with damage, injuries or deaths is the May 26, 2026 thunderstorm wind ($20,000 in damage in 2025 dollars).

Source: NOAA NCEI Storm Events Database; every record of 2025-2026 is listed, earlier ones when they caused deaths, injuries or $250,000 of damage (2025 dollars), and every tornado.

The deadliest and costliest records

A damage figure marked "step" is a record from before 1993: NOAA then filed damage by category, and the figure is the category as entered, in the dollars of that year, not an estimate of the loss.

Source: NOAA NCEI Storm Events Database: deaths and injuries direct and indirect; damage is property plus crops as estimated by the National Weather Service, converted to 2025 dollars.

Is it getting more frequent?

Records per decade for Williamson County's most frequent hazards. Counts rose everywhere after 1996, when NOAA began recording every event type, so compare decades within a hazard's complete period only (the shaded cells come before it).

Winter storms in the 2010s: 21 records against 6 in the decade before, 21 of them forecast-zone records. Cells marked z rose mostly through zone records. The local National Weather Service office files these once per forecast zone, so a change in how it draws its zones or splits a storm into records moves this count as much as the weather does; read it beside the Williamson County days with a record above.

Source: NOAA NCEI Storm Events Database, records per calendar decade; zone records from the CZ_TYPE field (Z).

What time of year?

59% of its hail reports since 1959 fell in April and May. The two busiest months are in violet.

Source: NOAA NCEI Storm Events Database, records by the month they began.

Federal disaster declarations for Williamson County

FEMA's register lists 26 declarations that include Williamson County: 13 major disasters, 9 emergencies and 4 fire management assistance declarations. Most were for fire (8) and severe storm (4).

Source: FEMA OpenFEMA Disaster Declarations Summaries (v2), declarations through October 2, 2026; one declaration is counted once however many areas it names. OpenFEMA dataset page.

How many floods has Williamson County had?

NOAA's Storm Events Database holds 171 flood or flash flood records for Williamson County from 1996 to 2026, on 110 days, with 5 deaths. By flood insurance claims since 1978 (OpenFEMA, as of September 8, 2026), Williamson County ranks 403rd of 2,942 U.S. counties.

The National Flood Insurance Program has paid $22.3 million on 741 claims filed in Williamson County; the most in one year was 210 in 2010. Claims count insured losses only: uninsured flood damage is not in this file.

Source: FEMA OpenFEMA NFIP Redacted Claims, as of September 8, 2026; claims by year of loss, payments in the dollars of the year paid. OpenFEMA dataset page.

FEMA's modeled risk for Williamson County

FEMA's National Risk Index rates Williamson County Relatively Moderate overall, with an expected annual loss of $137 million. These are FEMA's model estimates of future loss from 18 hazards, not a count of what happened; they can differ from the record above.

Source: FEMA National Risk Index, county table, December 2025 release. FEMA's National Risk Index map.

Counties that share a border with Williamson County

1. Travis County 1,371
2. Bell County 1,219
3. Williamson County 1,069
4. Burnet County 655
5. Bastrop County 490
6. Milam County 480
7. Lee County 316

Source: U.S. Census Bureau county adjacency file; NOAA NCEI Storm Events Database, records since 1950. The Census Bureau's adjacency file.

Next

• Tornadoes in TexasEvery Texas tornado since 1950 and the counties with the most per square mile
• Hail in TexasThe state's hail reports, by county, year and month
• The Texas recordEvery hazard in the state, its deadliest events and its federal declarations
• FEMA's risk rating for each hazard in Williamson CountyThe hazard risk calculator: 18 hazards beside the county's record
• Download Williamson County's FEMA declarations (CSV)26 rows: every declaration that named the county, for your own analysis