Williamson County, TX
FEMA National Risk Index scores, disaster declarations & hazard data
Williamson County has experienced 26 federally declared disasters since 1975, most recently Severe Storms, Straight-Line Winds, And Flooding in 2025. Its overall natural hazard risk is rated Relatively Moderate — near the middle compared to other US counties.
Williamson County's highest-rated hazards are hail, winter weather, and cold wave, with its top risk rated "Relatively High" by FEMA's National Risk Index. Recorded storm events have increased 119% over the past five years compared to the prior five-year period.
Past disasters & FEMA designations
A federal disaster declaration officially designates a county for FEMA disaster assistance. Williamson County has been designated in 26 declarations since 1975, covering 9 disaster types including fire (8), severe storm (4), hurricane (4).
| Year | Type | Event name |
|---|---|---|
| 2025 | Flood | Severe Storms, Straight-Line Winds, And Flooding |
| 2023 | Winter Storm | Severe Winter Storm |
| 2021 | Severe Ice Storm | Severe Winter Storms |
| 2021 | Severe Ice Storm | Severe Winter Storm |
| 2020 | Biological | Covid-19 Pandemic |
| 2020 | Biological | Covid-19 |
| 2015 | Severe Storm | Severe Storms, Tornadoes, Straight-Line Winds And Flooding |
| 2011 | Fire | Wildfires |
| 2011 | Fire | Moonglow Fire |
| 2011 | Fire | Horseshoe Fire |
Showing the 10 most recent of 26 total declarations since 1975.
Source: FEMA OpenFEMA Disaster Declarations Summaries. A single disaster can produce more than one record per county. Data current through September 2026.
Risk by hazard type
| Hazard | Risk rating | Risk score | Recorded events | Deaths | Prop. damage |
|---|---|---|---|---|---|
| Wildfire | Relatively Low | 87.8 | 0 | 0 | — |
| Inland Flooding | Relatively Moderate | 91.3 | 43 | 0 | $25.2M |
| Coastal Flooding | Not Applicable | — | 0 | 0 | — |
| Earthquake | Very Low | 36.5 | — | — | — |
| Heat Wave | Relatively Moderate | 91 | 5 | 0 | — |
| Tornado | Relatively High | 93.9 | 12 | 0 | $756K |
| Hurricane | Relatively Low | 69 | 0 | 0 | — |
| Hail | Relatively High | 98.7 | 203 | 0 | $300.0M |
| Strong Wind | Relatively Moderate | 55.9 | 0 | 0 | — |
| Winter Weather | Very High | 96.8 | 0 | 0 | — |
| Ice Storm | Relatively Moderate | 72.5 | — | — | — |
| Cold Wave | Relatively High | 95.9 | — | — | — |
| Lightning | Relatively High | 88.8 | 5 | 0 | $1.2M |
| Drought | Relatively Moderate | 72.4 | 0 | 0 | — |
| Landslide | Very Low | 24.1 | 0 | 0 | — |
| Avalanche | Not Applicable | — | — | — | — |
| Tsunami | Not Applicable | — | — | — | — |
| Volcanic Activity | Not Applicable | — | — | — | — |
Scores are 0–100 percentiles relative to all US counties — higher means more exposed, not that a disaster is likely this year. Event counts: NOAA Storm Events 2016–2026; earthquake counts from USGS ComCat (M3.0+, 1996–2026). See the methodology page for details.
Community vulnerability
Williamson County ranks in the 32nd percentile (Low) for community vulnerability — a measure of how hard disaster impacts tend to hit residents. Higher vulnerability means more displacement, worse health outcomes, and slower recovery after a disaster.
| SVI theme | Percentile | Vulnerability level |
|---|---|---|
| Overall | 32nd | Low |
| Socioeconomic status | 27th | Low |
| Household characteristics | 40th | Low |
| Racial & ethnic minority status | 82nd | High |
| Housing type & transportation | 23rd | Very low |
Source: CDC/ATSDR Social Vulnerability Index 2022. Percentiles compare counties nationally — higher means more vulnerable relative to other counties. See CDC SVI for full methodology.
Future risk outlook
| Wildfire metric | National percentile | Level |
|---|---|---|
| Burn probability | 65th | Relatively High |
| Risk to homes | 69th | Relatively High |
| Buildings in direct exposure zone | 31.8% | — |
NOAA tracked 268 weather events in this county over 2016–2025: 84 in 2016–20 vs 184 in 2021–25 (+119% — frequency increasing).
Wildfire: USDA Forest Service Wildfire Risk to Communities (RDS-2020-0016-2) — modeled values, not annual forecasts. See wildfirerisk.org. Inland flood and heat projections pending data availability; coastal sea-level projections are available for select coastal counties below — see the data page.
Nearby counties
Frequently asked questions
What natural hazards pose the greatest risk in Williamson County?
According to the FEMA National Risk Index, the highest-risk hazards in Williamson County, Texas are hail, winter weather, and cold wave. The county's overall natural hazard risk is rated Relatively Moderate — near the middle compared to other US counties.
Has Williamson County received federal disaster declarations?
Yes. Williamson County has received 26 federal disaster declarations since 1975, including declarations in 2025. The most common disaster type on record is fire (8 declarations).
Has Williamson County had any FEMA disaster declarations in 2024, 2025, or 2026?
Yes. Recent federal disaster declarations for Williamson County include Severe Storms, Straight-Line Winds, And Flooding (2025). See the declarations table above for the full history since 1975.
How does Williamson County's natural hazard risk compare to nearby counties?
Among neighboring counties, Travis County, TX has the highest overall natural hazard risk (Relatively High) and Lee County, TX has the lowest (Very Low). Williamson County is rated Relatively Moderate overall.
How is Williamson County's composite disaster risk index calculated?
Williamson County's composite disaster risk index — officially FEMA's National Risk Index (NRI) — scores every US county on a 0–100 percentile scale across 18 natural hazard types, factoring in expected annual loss, social vulnerability, and community resilience. Williamson County's composite score of 90 means its overall natural hazard risk is higher than 90% of US counties.