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Williamson County, Illinois severe weather history spans 375 recorded events between 1957 and 2025. The dominant hazard is thunderstorm wind, accounting for 36.5% of all recorded events. It ranks #1,356 nationally and #46 in Illinois.
375
Recorded events
11
Direct deaths
215
Direct injuries
$495.6M
Property damage
The record
What the Williamson County, Illinois severe weather history record shows
Across the archive, Williamson County, Illinois severe weather history averages 5.5 recorded events a year. The busiest stretch on record is the 2010s, with 124 events logged in that decade alone. Roughly 28 events fall before 1990 and 347 from 1990 onward — a gap that reflects the expansion of NOAA reporting practice as much as the weather itself.
The deadliest hazard in the Williamson County, Illinois record is tornado, responsible for 10 direct deaths. The costliest is tornado, with $303.9M in reported property damage. In total, 8 distinct hazard types appear in this county archive, each listed with its own dated record below.
By hazard type
Every hazard type recorded in Williamson County
| Hazard | Events | Deaths | Damage | Max | Span |
|---|---|---|---|---|---|
| Thunderstorm Wind | 137 | 0 | $176.8M | 87 | 1966–2025 |
| Hail | 120 | 0 | $12.4M | 3 | 1971–2025 |
| Flash Flood | 40 | 0 | $1.9M | 0 | 1996–2025 |
| Flood | 23 | 1 | $520K | 0 | 1996–2024 |
| Tornado | 22 | 10 | $303.9M | F4 | 1957–2025 |
| Heavy Rain | 20 | 0 | $0 | 0 | 2003–2015 |
| Funnel Cloud | 10 | 0 | $0 | 0 | 2005–2017 |
| Lightning | 3 | 0 | $130K | 0 | 2006–2011 |
Decade by decade
Williamson County, Illinois severe weather history by decade
Reporting practice changed over time — early decades are undercounted, not calmer.
Tornado tracks
Paths crossing this county
23 mapped tornado paths intersect this county: 20 touched down inside it and 3 crossed in from a neighbouring county. This comes from path geometry, not county-tagged reports.
| Date | Scale | Deaths | Injuries | Path length | Origin |
|---|---|---|---|---|---|
| 1957-12-18 | EF4 | 11 | 200 | 28.3 mi | Crossed in |
| 1982-05-29 | EF4 | 10 | 181 | 17.0 mi | Touched down here |
| 2025-05-16 | EF4 | 0 | 7 | 16.3 mi | Touched down here |
| 1991-11-19 | EF3 | 0 | 16 | 1.5 mi | Touched down here |
| 2024-04-02 | EF2 | 0 | 0 | 6.7 mi | Touched down here |
| 2018-04-03 | EF2 | 0 | 0 | 12.4 mi | Touched down here |
| 2012-02-29 | EF2 | 0 | 0 | 14.9 mi | Touched down here |
| 1973-06-02 | EF2 | 0 | 0 | 0.1 mi | Touched down here |
| 2025-04-02 | EF1 | 0 | 0 | 3.3 mi | Touched down here |
| 2024-04-02 | EF1 | 0 | 0 | 7.6 mi | Touched down here |
Significant events
Deadliest events on record in Williamson County
| Date | Type | Location | Deaths | Injuries | Damage |
|---|---|---|---|---|---|
| May 29, 1982 | Tornado | 10 | 181 | $250.0M | |
| Aug 3, 2000 | Flood | MARION | 1 | 0 | $0 |
| Nov 19, 1991 | Tornado | 0 | 16 | $25.0M | |
| Dec 18, 1957 | Tornado | 0 | 10 | $2.5M | |
| May 16, 2025 | Tornado | WOLF CREEK | 0 | 7 | $25.0M |
| May 8, 2009 | Thunderstorm Wind | CARTERVILLE | 0 | 1 | $175.0M |
From the record
What the reports say
Written by National Weather Service staff at the time of the event · public domain
Very heavy rain from a slow-moving thunderstorm caused streets to flood and ditches to run full. A 9-year-old boy attempting to retrieve an object from a culvert was swept into it by rushing water. He later died at a hospital in St. Louis.
Giant hail occurred in a swath of Williamson County along Illinois Route 13. The swath of large hail began near the Marion/Williamson County airport, just east and southeast of Crainville. Hail slightly larger than baseballs pounded the area in the immediate vicinity of the Marion/Williamson County Regional Airport. Hail damage was reported to planes at the airport, including broken windows. Numerous vehicles were damaged by hail from quarter size to golf-ball size. Hail damage occurred at the baseball stadium near Interstate 57 at Route 13. There was major damage to multiple vehicles at a car dealership on Route 13 between the Marion airport and the downtown Marion area. The large hail swath continued into the north side of the city of Marion, where hail the size of golf balls occurred.
In Marion, firefighters used boats to rescue 13 residents of the city's housing project. Water was up to a foot deep in some apartments. Five stranded motorists were rescued by Marion firefighters. A total of 21 persons were rescued by boat by firefighters in the city of Marion. At least a few vehicles were submerged up to their headlights. Victims were transported to a Red Cross shelter. A Marion official stated this was the worst flood since May of 1996, before the flood control project was completed. Many streets were underwater, including the main access road to Marion High School. An SUV was stranded in floodwaters. In Johnston City, most roadways were closed. A bridge was taken out by floodwaters on a side street. Route 148 was closed north of the Crab Orchard bridge. Numerous county roads were closed. Ten basements were flooded in Herrin.
Context
Risk, population and federal disasters
Relatively Moderate
FEMA NRI risk rating
66,876
Population (ACS)
$156K
Median home value
9
Federal declarations
| Declared | Incident | Title | Type |
|---|---|---|---|
| Mar 26, 2020 | Biological | COVID-19 PANDEMIC | DR |
| Mar 13, 2020 | Biological | COVID-19 | EM |
| Jun 7, 2011 | Severe Storm | SEVERE STORMS AND FLOODING | DR |
| Jul 2, 2009 | Severe Storm | SEVERE STORMS, FLOODING, AND TORNADOES | DR |
| Sep 7, 2005 | Hurricane | HURRICANE KATRINA EVACUATION | EM |
| Feb 1, 2005 | Snowstorm | RECORD/NEAR RECORD SNOW | EM |
Within the county
Most affected places
- Marion 142
Quick answers
Frequently asked
How many severe weather events have been recorded in Williamson County, Illinois?
375 events are on record between 1957 and 2025, causing 11 direct deaths and $495.6M in property damage.
What is the most common severe weather hazard in Williamson County?
Thunderstorm Wind, with 137 recorded events — 36.5% of everything in the archive for this county.
How many tornadoes have crossed Williamson County?
23 mapped tornado paths intersect the county boundary; 20 of them touched down inside it. This is derived from path geometry, not county-tagged reports.
How many federal disaster declarations cover Williamson County?
9 federal disaster declarations from FEMA include Williamson County, each tied to a specific incident period.
How risky is Williamson County compared with the rest of the country?
FEMA's National Risk Index rates Williamson County as relatively moderate risk, placing it in the 86 percentile of its state for expected annual loss.
Where does the Williamson County, Illinois severe weather history data come from?
Every figure is drawn from United States federal public-domain records: NOAA/NCEI Storm Events for the event archive, NOAA SPC SVRGIS for mapped tornado paths, FEMA for disaster declarations and risk ratings, and the U.S. Census for population context. Dates are shown in UTC and recent entries may still be revised by NOAA.
Nearby
Neighbouring counties
- Will County 1,250
- Winnebago County 692
- Whiteside County 557
- Woodford County 437
- White County 413
- Wayne County 312
Cite this page
“Williamson County, Illinois.” Severe Weather History. severeweatherhistory.com/county/illinois/williamson-county/ · Data: NOAA/NCEI, FEMA, U.S. Census — public domain.