Williamson County, Texas: Natural Disaster Risk and History
Williamson County, Texas has a Relatively Moderate natural-hazard risk rating in FEMA's National Risk Index (v1.20, December 2025): a score of 90.1 out of 100, higher than about 90% of US counties, with hail, winter storms and cold waves scoring highest of its 18 hazards and $137 million a year in expected losses.
OpenFEMA lists 24 federal disaster declarations that included Williamson County since 1974, not counting 2 for COVID-19; the latest is DR-4879-TX (Severe Storms, Straight-Line Winds, and Flooding, declared 6 July 2025). NOAA's Storm Prediction Center recorded 73 tornadoes touching Williamson County from 1950 to 2025.
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Population 608,015 Buildings worth $97 billion Area 1,143 sq mi Risk rank in Texas 24 of 254 FIPS 48491
All 18 hazards, highest risk first
FEMA National Risk Index| Hazard | Risk rating | Score | Expected loss a year | How often | Events in record |
|---|---|---|---|---|---|
| Hail | Relatively High | 98.7 | $14 million | about 4 a year | 150 |
| Winter weather | Very High | 96.8 | $1.5 million | about 3.7 a year | 71 |
| Cold wave | Relatively High | 95.9 | $21 million | about once every 1.6 years | 12 |
| Tornado | Relatively High | 93.9 | $17 million | about once every 1.6 years | 51 |
| Inland flooding | Relatively Moderate | 91.3 | $71 million | about 3.6 a year | 102 |
| Heat wave | Relatively Moderate | 91.0 | $5.3 million | about 1 a year | 160 |
| Lightning | Relatively High | 88.8 | $1.8 million | about 49 a year | 446,533 strikes |
| Wildfire | Relatively Low | 87.8 | $1.6 million | about once every 962 years | — |
| Ice storm | Relatively Moderate | 72.5 | $402,550 | about once every 1.5 years | 44 |
| Drought | Relatively Moderate | 72.4 | $964,396 | about 59 a year | 2,296 |
| Hurricane | Relatively Low | 69.0 | $860,306 | about once every 27 years | 14 |
| Strong wind | Relatively Moderate | 55.9 | $1.0 million | about 1.7 a year | 66 |
| Earthquake | Very Low | 36.5 | $196,884 | rarer than once in 1,000 years | — |
| Landslide | Very Low | 24.1 | $278 | about once every 7.8 years | — |
| 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 24
Most common: Fire 8, Severe Storm 4, Hurricane 4, Flood 3.
| Decade | Declarations | Incident types |
|---|---|---|
| 1970s | 1 | Flood |
| 1980s | 1 | Severe Storm |
| 1990s | 4 | Fire, Severe Storm, Drought, Flood |
| 2000s | 9 | Hurricane ×4, Fire ×3, Severe Storm, Other |
| 2010s | 5 | Fire ×4, Severe Storm |
| 2020s | 4 | Severe Ice Storm ×2, Flood, Winter Storm |
The last 10
Widest declarations that included Williamson County
- Severe Winter Storms (2021, DR-4586-TX): 254 Texas counties designated.
- Severe Winter Storm (2021, EM-3554-TX): 254 Texas counties designated.
- Extreme Wildfire Threat (2006, DR-1624-TX): 254 Texas counties designated.
Named storms in its declarations: Hurricane Ike (2008), Hurricane Rita (2005), Hurricane Katrina (2005), Tropical Storm Charley (1998).
Not counted above: 2 COVID-19 ("Biological") declarations — in 2020 every US county was included. Texas also had 101 statewide declarations with no county list.
Tornado record since 1950 73
| Tornadoes touching the county | 73 |
|---|---|
| Strongest-rated | (E)F5 ×1 |
| Peak month | May (24) |
| Deadliest | 27 May 1997, F5, 5.1 mi path, 27 killed, 12 injured |
| Longest path | 30 Apr 1954, F3, 139.9 mi path, 0 killed, 6 injured |
| Most recent | 24 Oct 2022, EF1, 3.9 mi path |
| Deaths / injuries on those paths | 29 / 97 |
| Rating | (E)F0 | (E)F1 | (E)F2 | (E)F3 | (E)F4 | (E)F5 | Unrated |
|---|---|---|---|---|---|---|---|
| Count | 24 | 27 | 15 | 6 | 0 | 1 | 0 |
| Decade | 1950s | 1960s | 1970s | 1980s | 1990s | 2000s | 2010s | 2020s |
|---|---|---|---|---|---|---|---|---|
| Count | 6 | 9 | 11 | 12 | 8 | 10 | 13 | 4 |
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 Williamson County compares with its 5 nearest counties
| County | Distance | Overall risk | Score | Top hazard |
|---|---|---|---|---|
| Williamson County (this page) | — | Relatively Moderate | 90.1 | Hail |
| Travis County | 39 km | Relatively High | 97.7 | Tornado |
| Bell County | 45 km | Relatively Moderate | 91.1 | Hail |
| Burnet County | 58 km | Relatively Low | 76.6 | Wildfire |
| Milam County | 62 km | Relatively Low | 58.1 | Drought |
| Bastrop County | 67 km | Relatively Moderate | 81.2 | Tornado |
Nearest by distance between county centres. Every county in Texas, ranked.
Vulnerability and resilience
| Social vulnerability | Very Low 10.6 |
|---|---|
| Community resilience | Very High 87.9 |
| Community risk factor | 0.65 |
| Expected annual loss, all hazards | $137 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 Williamson County's main hazards
- Right now: National Weather Service alerts for Texas · all official warnings on Global Incident Tracker.
- Hail: Weather alerts for Texas
- Winter weather: Power outages now · Carbon monoxide in winter
- Cold wave: Carbon monoxide in winter · Power outages 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 Williamson County
What natural disasters is Williamson County, Texas most at risk from?
Williamson County, Texas has a Relatively Moderate natural-hazard risk rating in FEMA's National Risk Index (v1.20, December 2025): a score of 90.1 out of 100, higher than about 90% of US counties, with hail, winter storms and cold waves scoring highest of its 18 hazards and $137 million a year in expected losses.
How many federal disaster declarations has Williamson County had?
OpenFEMA lists 24 federal disaster declarations that included Williamson County since 1974, not counting 2 for COVID-19; the latest is DR-4879-TX (Severe Storms, Straight-Line Winds, and Flooding, declared 6 July 2025). Another 101 Texas declarations were made statewide without a county list.
How many tornadoes have hit Williamson County?
NOAA's Storm Prediction Center recorded 73 tornadoes touching Williamson County from 1950 to 2025. The deadliest: 27 May 1997, F5, 5.1 mi path, 27 killed, 12 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.