Williamson County, Texas: hazard history
What federal records show has already happened here: disaster declarations, storms, and flood insurance claims. This is a record of the past. It is not a forecast and not a hazard score.
At a glance
What this means
- The event NOAA recorded most often here is Hail, with 372 records.
- The costliest single record is Hail in 2023: $300.0M in property damage, in the dollars of that year.
- The deadliest record is Tornado in 1997, with 27 deaths.
- FEMA has declared 26 disasters that named this county, most often for fire.
- The worst year for flood insurance claims was 2010, with 210 claims.
What this can't tell you
- What happens next. Past events do not set the odds of the next one.
- Anything before 1996 from NOAA. That is when NOAA began recording every event type; earlier files hold only tornado, hail and wind, so they are left out on purpose.
- Today's cost. Damage and payments are in the dollars of the year they happened.
- A flood rate. NFIP counts claims but not how many homes were insured, and many flooded homes carry no flood insurance.
- Earthquakes, wildfire perimeters or radar-detected hail. Those records are not tied to counties.
Federal disaster declarations (FEMA)
FEMA declared 26 disasters that named Williamson County between 1974 and 2025.
| Incident type | Disasters | Most recent |
|---|---|---|
| Fire | 8 | 2011 |
| Hurricane | 4 | 2008 |
| Severe Storm | 4 | 2015 |
| Flood | 3 | 2025 |
| Biological | 2 | 2020 |
| Severe Ice Storm | 2 | 2021 |
| Drought | 1 | 1993 |
| Other | 1 | 2003 |
| Winter Storm | 1 | 2023 |
Most recent declarations
- DR-4879 2025 · Flood · Severe Storms, Straight-line Winds, And Flooding
- DR-4705 2023 · Winter Storm · Severe Winter Storm
- EM-3554 2021 · Severe Ice Storm · Severe Winter Storm
- DR-4586 2021 · Severe Ice Storm · Severe Winter Storms
- EM-3458 2020 · Biological · Covid-19
- DR-4485 2020 · Biological · Covid-19 Pandemic
- DR-4223 2015 · Severe Storm · Severe Storms, Tornadoes, Straight-line Winds And Flooding
- FM-2963 2011 · Fire · Moonglow Fire
- DR-4029 2011 · Fire · Wildfires
- FM-2949 2011 · Fire · Horseshoe Fire
Not counted above: 102 statewide declarations, which covered every county in Texas. A declaration is a decision to send federal help, not a measure of how bad an event was. Records run from 1953. Source: FEMA OpenFEMA Disaster Declarations Summaries.
Storms recorded by NOAA, by type
| Event type | Records | Deaths | Injuries | Property damage |
|---|---|---|---|---|
| Hail | 372 | 0 | 0 | $300.3M |
| Flash Flood | 157 | 5 | 10 | $35.5M |
| Thunderstorm Wind | 141 | 0 | 2 | $3.0M |
| Drought | 75 | 0 | 0 | $0 |
| Tornado | 32 | 27 | 27 | $112.2M |
| Winter Weather | 23 | 0 | 0 | $0 |
| Winter Storm | 22 | 1 | 0 | $22.9M |
| Lightning | 9 | 1 | 0 | $1.3M |
| Funnel Cloud | 8 | 0 | 0 | $0 |
| Flood | 7 | 0 | 0 | $30K |
| Excessive Heat | 5 | 0 | 0 | $0 |
| Wildfire | 5 | 0 | 0 | $4.2M |
| Extreme Cold/Wind Chill | 4 | 2 | 0 | $0 |
| Cold/Wind Chill | 3 | 0 | 0 | $0 |
| High Wind | 3 | 0 | 0 | $0 |
| Heat | 1 | 1 | 0 | $0 |
| Heavy Rain | 1 | 1 | 0 | $0 |
| Strong Wind | 1 | 0 | 0 | $10K |
Records start in 1996. Damage is NOAA's estimate at the time, in nominal dollars, and is often rounded; it is not insurance claims data. A storm that crossed two NOAA zones in this county is recorded, and counted, once per zone. A storm filed against a forecast zone is counted in every county that zone covers, with the whole storm's damage; do not add these figures across counties.
Year by year
NOAA storm event records in Williamson County each year. The busiest year was 2025, with 93 records.
Show the numbers for every year
| Year | Records | Deaths | Property damage |
|---|---|---|---|
| 1996 | 20 | 0 | $69K |
| 1997 | 21 | 27 | $110.6M |
| 1998 | 20 | 1 | $290K |
| 1999 | 16 | 0 | $156K |
| 2000 | 21 | 1 | $490K |
| 2001 | 16 | 2 | $1.4M |
| 2002 | 22 | 0 | $730K |
| 2003 | 8 | 0 | $155K |
| 2004 | 22 | 0 | $105K |
| 2005 | 17 | 0 | $0 |
| 2006 | 26 | 0 | $230K |
| 2007 | 22 | 1 | $710K |
| 2008 | 28 | 0 | $250K |
| 2009 | 50 | 1 | $1.3M |
| 2010 | 12 | 1 | $25K |
| 2011 | 29 | 0 | $2.3M |
| 2012 | 26 | 0 | $16K |
| 2013 | 32 | 0 | $1.1M |
| 2014 | 14 | 0 | $0 |
| 2015 | 31 | 2 | $7.1M |
| 2016 | 16 | 0 | $0 |
| 2017 | 35 | 0 | $1.3M |
| 2018 | 31 | 0 | $338K |
| 2019 | 27 | 0 | $12K |
| 2020 | 24 | 0 | $47K |
| 2021 | 22 | 2 | $255K |
| 2022 | 41 | 0 | $694K |
| 2023 | 71 | 0 | $324.6M |
| 2024 | 26 | 0 | $0 |
| 2025 | 93 | 0 | $25.0M |
| 2026 | 30 | 0 | $60K |
Years with no record are left out of the table, not shown as zero.
Notable events
Costliest records
- Hail · Sep 24, 2023$300.0MNOAA name: Williamson County · NOAA record 1140534
- Tornado · May 27, 1997$70.0MNOAA name: Williamson County · 15 injuries · NOAA record 5598914
- Tornado · May 27, 1997$40.0MNOAA name: Williamson County · 27 deaths · 12 injuries · NOAA record 5598913
- Flash Flood · Jul 5, 2025$25.0MNOAA name: Williamson County · NOAA record 1288021
- Winter Storm · Feb 1, 2023$22.6MNOAA name: NWS forecast zone · NOAA record 1081609
Deadliest records
- Tornado · May 27, 199727 deathsNOAA name: Williamson County · $40.0M damage · 12 injuries · NOAA record 5598913
- Flash Flood · Nov 15, 20012 deathsNOAA name: Williamson County · $500K damage · 10 injuries · NOAA record 5272979
- Extreme Cold/Wind Chill · Feb 14, 20212 deathsNOAA name: NWS forecast zone · NOAA record 943800
- Lightning · Jul 19, 19981 deathNOAA name: Williamson County · NOAA record 5658366
- Heat · Jul 25, 20001 deathNOAA name: NWS forecast zone · NOAA record 5170797
Each line is one NOAA record, linked to its page at NOAA. One large storm can appear more than once if NOAA recorded it in several zones of this county. Dollars are nominal.
Flood insurance claims (NFIP)
The National Flood Insurance Program paid $18.7M on 693 claims in Williamson County from 1979 to 2023.
| Year | Claims | Paid |
|---|---|---|
| 2010 | 210 | $10.7M |
| 2015 | 67 | $2.8M |
| 1984 | 66 | $678K |
| 1981 | 48 | $355K |
| 1982 | 44 | $456K |
A count of claims, not a rate: NFIP publishes no count of insured homes beside it, and most flood damage is uninsured. Nominal dollars. Records run from 1978 to 2024; claims filed without a county code are not on any county page. Source: FEMA OpenFEMA FIMA NFIP Redacted Claims.
Hazard vulnerability analysis: the probability column for a facility in Williamson County
A hazard vulnerability analysis rates each hazard for probability, impact, preparedness and response. Probability is the one column the county’s federal record can fill — NCEI storm events from 1996 to 2026 and FEMA declarations naming the county — and this is what it says for a facility here, on the 0–3 scale of the all-hazards structure surveyors expect. The other six columns are the facility’s own judgment about its building, and Calchis leaves them blank.
| Hazard | Prob. | Basis, from the county record |
|---|---|---|
| Hurricane / Tropical Storm | 3 | No events of this kind on the county's NCEI record over 31 years. 4 federal disaster declarations naming the county. |
| Tornado | 3 | 32 NCEI events over 31 years (1.03/yr). No federal disaster declaration of this kind has named the county. |
| Severe Thunderstorm | 3 | 522 NCEI events over 31 years (16.84/yr). 4 federal disaster declarations naming the county. |
| Flood, External | 3 | 165 NCEI events over 31 years (5.32/yr). 3 federal disaster declarations naming the county. |
| Snow Fall / Blizzard / Ice Storm | 3 | 45 NCEI events over 31 years (1.45/yr). 2 federal disaster declarations naming the county. |
| Drought | 3 | 75 NCEI events over 31 years (2.42/yr). 1 federal disaster declaration naming the county. |
| Wild Fire | 3 | 5 NCEI events over 31 years (0.16/yr). 8 federal disaster declarations naming the county. |
| Temperature Extremes | 2 | 13 NCEI events over 31 years (0.42/yr). No federal disaster declaration of this kind has named the county. |
| High Wind (non-convective) | 2 | 4 NCEI events over 31 years (0.13/yr). No federal disaster declaration of this kind has named the county. |
| Epidemic | 2 | 2 federal disaster declarations naming the county. |
| Earthquake | 1 | No federal disaster declaration of this kind has named the county. |
| Landslide | 1 | No events of this kind on the county's NCEI record over 31 years. No federal disaster declaration of this kind has named the county. |
| Tidal Wave / Tsunami | 1 | No events of this kind on the county's NCEI record over 31 years. No federal disaster declaration of this kind has named the county. |
| Volcano | 1 | No events of this kind on the county's NCEI record over 31 years. No federal disaster declaration of this kind has named the county. |
| Dam Inundation | 1 | No federal disaster declaration of this kind has named the county. |
A dash means the record does not speak to that hazard; it is not a zero. Whether a finished document satisfies the CMS Emergency Preparedness Rule is the facility’s finding and its surveyor’s. Complete the HVA for a facility in Williamson County — the technological, human and hazardous-materials rows, the six facility columns, the approval and the printed document — or read the sample analysis on that page first.
How this page was made
- Every figure is counted from public federal records held by Calchis: NOAA NCEI Storm Events, FEMA OpenFEMA Disaster Declarations, and FEMA NFIP claims. Nothing is modeled or estimated.
- NOAA files some events against a county and others against an NWS forecast zone, and publishes a code for both. Records are counted as Williamson County by that code — county records by the county's own FIPS code, zone records through the National Weather Service's published list of which counties each zone covers. No name matching is involved. Of 869 records, 724 were filed against this county and 145 against a forecast zone covering it. A zone storm is counted in every county its zone covers, and its damage figure is the whole storm's, not this county's share — NOAA does not publish that split. So these figures describe this county; they must not be added up across counties. Left out: 1% of Texas's NOAA records, which are marine zones or zones NWS does not map to a county.
- Counts last rebuilt from the source records on Sep 15, 2026.
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Recorded history from federal public records. Not a hazard score, a risk score, or a forecast, and not a substitute for professional actuarial or emergency-management assessment. Decision-support intelligence — not a primary alerting or dispatch system. Verify against official sources.