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Tornado in Williamson County, Illinois
22 tornadoes events in the NCEI Storm Events record, 1950 to 2026. Event types counted: Tornado.
NCEI notes that Storm Data is compiled from a variety of sources including the National Weather Service, other federal, state and local agencies, the media and the public; that property and crop damage figures are estimates; and that some events are recorded by NWS forecast zone rather than by county. FEMA notes that NFIP claim records are redacted and aggregated to protect the privacy of policyholders. Storm records through 30 Jun 2026.
NCEI records 22 tornado events in Williamson County, Illinois, between 1950 and 2026, spread over 15 years.
April is the busiest month, with 8 of the recorded events. The last 20 years account for 15 events against 3 in the 20 years before, a change that reflects reporting practice as much as weather.
The county holds 0.6% of the 3,647 tornado events recorded in Illinois; its 5.2 per 100 square miles compares with 6.6 statewide.
NCEI attributes 10 deaths in the county to tornadoes.
By rating: 2 at (E)F0, 13 at (E)F1, 3 at (E)F2, 1 at (E)F3, 3 at (E)F4, 0 at (E)F5. Tornadoes before 2007 carry the original Fujita rating.
Compared with Illinois
| Measure | Williamson County | Illinois | US |
|---|---|---|---|
| Tornado events since 1950 | 22 | 3,647 | 81,281 |
| Per 100 square miles | 5.2 | 6.6 | 2.3 |
| Per 10,000 residents | 3.3 | 2.9 | 2.4 |
| Deaths recorded | 10 | 236 | 6,410 |
| Busiest month | April | April | May |
By year
Seasonality
0Feb
2Mar
0Apr
8May
5Jun
3Jul
0Aug
0Sep
0Oct
2Nov
1Dec
1
Magnitude distribution
Enhanced Fujita scale wind estimates
- EF0/F0
- 65–85 mph (EF0)
- EF1/F1
- 86–110 mph (EF1)
- EF2/F2
- 111–135 mph (EF2)
- EF3/F3
- 136–165 mph (EF3)
- EF4/F4
- 166–200 mph (EF4)
- EF5/F5
- over 200 mph (EF5)
- Unrated
- no rating recorded
Tornado rating as recorded (Fujita scale before February 2007, Enhanced Fujita after).
Recorded events
All 22 events, most recent first. Magnitude is hail size, tornado rating or wind speed as recorded.
| Date | Event type | Magnitude | Property damage | Crop damage | Deaths | Injuries | Geography |
|---|---|---|---|---|---|---|---|
| 16 May 2025 | Tornado | EF4 | $25M | — | — | 7 | County |
| 8 May 2024 | Tornado | EF0 | $10K | — | — | — | County |
| 8 May 2024 | Tornado | EF1 | $10K | — | — | — | County |
| 2 Apr 2024 | Tornado | EF2 | $300K | — | — | — | County |
| 2 Apr 2024 | Tornado | EF1 | $130K | — | — | — | County |
| 28 Jun 2018 | Tornado | EF0 | $35K | — | — | — | County |
| 3 Apr 2018 | Tornado | EF1 | $250K | — | — | — | County |
| 3 Apr 2018 | Tornado | EF1 | $40K | — | — | — | County |
| 3 Apr 2018 | Tornado | EF1 | $7K | — | — | — | County |
| 5 Apr 2017 | Tornado | EF1 | $35K | — | — | — | County |
| 28 Feb 2017 | Tornado | EF1 | $6K | — | — | — | County |
| 3 Apr 2014 | Tornado | EF1 | $10K | — | — | — | County |
| 31 Oct 2013 | Tornado | EF1 | $40K | — | — | — | County |
| 29 Feb 2012 | Tornado | EF2 | $100K | — | — | — | County |
| 8 May 2009 | Tornado | EF1 | — | — | — | — | County |
| 18 Oct 2004 | Tornado | F1 | $25K | — | — | — | County |
| 12 Jun 1998 | Tornado | F1 | $100K | — | — | — | County |
| 19 Nov 1991 | Tornado | F3 | $25M | — | — | 16 | County |
| 29 May 1982 | Tornado | F4 | $250M | — | 10 | 181 | County |
| 2 Jun 1973 | Tornado | F2 | $250K | — | — | — | County |
| 3 Apr 1968 | Tornado | F1 | $25K | — | — | — | County |
| 18 Dec 1957 | Tornado | F4 | $2.5M | — | — | 10 | County |
Questions and answers
How many tornado events has Williamson County had?
22 events in the NCEI Storm Events record between 1950 and 2026. Reporting of tornadoes became far more complete after 1996, so early decades undercount.
When was the last recorded tornado event in Williamson County?
16 May 2025 (Tornado, EF4). Records reach NCEI about 120 days after the month ends.
What was the most damaging tornado event recorded in Williamson County?
The tornado of 29 May 1982, with property damage estimated by NCEI at $250M; 10 deaths recorded.
How does Williamson County compare with Illinois for tornado?
5.2 events per 100 square miles against 6.6 statewide; the county holds 22 of the state's 3,647 recorded events.
Provenance
NOAA NCEI Storm Events Database, yearly details files through 30 Jun 2026, public domain. County-recorded events plus zone-recorded events whose forecast zone is named for the county (marked "Forecast zone"). Population and area from the US Census Bureau (2021). Built 1 Oct 2026. See the methodology, the Tornado hub and the county page.