Enter any address in Williamson County, Texas to see its FEMA flood zone
Flash flooding from intense thunderstorms is the primary flood hazard in Williamson County, TX. Between 1993 and 2023, the NOAA Storm Events Database recorded 153 flash flood events, resulting in 5 fatalities, alongside 7 general flood events. For example, on July 5, 2025, extreme rainfall of 12-16 inches in six hours led to deadly flash flooding in neighboring counties, highlighting the potential for severe inundation.
National Flood Insurance Program (NFIP) data shows that properties in Zone A, which have a higher flood risk, accounted for the largest number of claims (298) with an average payout of $34,358 and an average water depth of 6.4 feet. Properties in Zone X also experienced significant claims (170) with a slightly higher average payout of $35,146, though with an average water depth of 4.1 feet. Homeowners in Zone A, and those in areas with a history of claims regardless of designated zone, should pay close attention to flood risk.
Summary generated from NOAA storm narratives and NFIP claim data for this county. Not predictive.
33 NOAA storm reports from this county describe what happened, in the words of the meteorologists who were there.
Williamson County, Texas has recorded 160 flood-related events since 1996 according to NOAA's Storm Events Database, including 153 flash floods and 7 river or area floods. The county has received 26 federal disaster declarations, 3 of which involved flooding or coastal storms. Enter any address above to check its FEMA flood zone designation.
FEMA Disaster Declarations (1974–2025)
Source: OpenFEMA Disaster Declarations Summaries.
| Declaration | Type | Date |
|---|---|---|
| Severe Storms, Straight-line Winds, And Flooding | Flood | Jul 2, 2025 |
| Severe Winter Storm | Winter Storm | Jan 30, 2023 |
| Severe Winter Storm | Severe Ice Storm | Feb 11, 2021 |
| Severe Winter Storms | Severe Ice Storm | Feb 11, 2021 |
| Covid-19 | Biological | Jan 20, 2020 |
| Covid-19 Pandemic | Biological | Jan 20, 2020 |
| Severe Storms, Tornadoes, Straight-line Winds And Flooding | Severe Storm | May 4, 2015 |
| Moonglow Fire | Fire | Sep 5, 2011 |
| Wildfires | Fire | Aug 30, 2011 |
| Horseshoe Fire | Fire | Aug 15, 2011 |
NOAA Storm Events Database (1996–2025)
Source: NOAA National Weather Service Storm Events Database.
| Type | Date | Damage |
|---|---|---|
| Flash Flood | May 6, 2025 | 0.00K |
| Flash Flood | Jul 5, 2025 | 0.00K |
| Flash Flood | Jul 5, 2025 | 25.00M |
| Flash Flood | Apr 20, 2023 | 0.00K |
| Flash Flood | Aug 27, 2022 | 0.00K |
| Flash Flood | May 1, 2021 | 0.00K |
| Flood | Jun 23, 2020 | 0.00K |
| Flash Flood | Apr 6, 2019 | 0.00K |
| Flash Flood | Mar 28, 2018 | 0.00K |
| Flash Flood | Dec 27, 2018 | 0.00K |
Flash Flood — May 6, 2025
Thunderstorms developed along a cold front as it moved through South-Central Texas. Some of these storms produced large hail and heavy rain that led to flash flooding.
Flash Flood — Jul 5, 2025
Precipitable water values over South-Central Texas remained near record levels, and a mid-level anticyclonic circulation continued over Central Texas providing lift to generate thunderstorms. These storms were efficient rain making storms leading to another night of excessive rainfall. Parts of Burnet and Travis Counties received 12-16 inches of rain in approximately six hours that led to deadl...
Flash Flood — Apr 20, 2023
An upper level trough moved across the southwest US and brought a cold front through Central Texas. Thunderstorms developed in the warm, moist airmass south of the front in response to a mid-level shortwave trough. Some of these storms produced severe weather including one tornado.
Flash Flood — Aug 27, 2022
Thunderstorms developed along a stationary front and one of these storms produced heavy rain that led to flash flooding.
Flash Flood — May 1, 2021
An upper level low over the Big Bend region combined with a surface low over South Texas to generate thunderstorms. The airmass in which these storms developed was very moist with precipitable water values above the 90th percentile of the long term record. Some of these storms produced locally heavy rain that led to flash flooding.
Source: NOAA National Weather Service Storm Events Database.
Source: OpenFEMA NFIP Individual Claims (2.25M records analyzed).
FEMA assigns flood zone designations to areas in Williamson County, Texas:
AE High Risk — 1% annual chance of flooding. Insurance required.
VE Very High Risk — Coastal flooding with wave action.
X (Shaded) Moderate Risk — 500-year floodplain.
X Low Risk — Outside major floodplains.
Properties in Williamson County, Texas that are in FEMA-designated Special Flood Hazard Areas (zones A and V) with federally backed mortgages are required to carry flood insurance.
Even outside high-risk zones, flood insurance is recommended. From 2014 to 2024, nearly one-third of NFIP claims came from outside the high-risk Special Flood Hazard Area.
Visit FloodSmart.gov to find an agent and get a quote.