Illinois recorded 3,010 tornadoes from 1950 through 2024, an average of 40 a year, in NOAA’s Storm Prediction Center database. They killed 235 people. The busiest year was 2024, with 142.
Tornadoes per 1,000 square miles since 1950: none under 10 10 to 25 25 to 50 50 to 75 75 to 100 over 100. Tap a county for its history.
Tornadoes by year
The rise since the 1990s is mostly better detection of weak tornadoes, not a jump in strong ones.
Tornado season in Illinois
May is the peak, with 648 tornadoes since 1950 (22% of the total).
How strong
| Rating | Estimated 3-second gust | Tornadoes |
|---|---|---|
| F0 / EF0 | Light damage: 65 to 85 mph (EF scale) | 1,327 |
| F1 / EF1 | Moderate: 86 to 110 mph | 993 |
| F2 / EF2 | Considerable: 111 to 135 mph | 429 |
| F3 / EF3 | Severe: 136 to 165 mph | 117 |
| F4 / EF4 | Devastating: 166 to 200 mph | 31 |
| F5 / EF5 | Incredible: over 200 mph | 2 |
| EF-U | Unknown: no damage to rate (mostly since 2016) | 111 |
Illinois has had 2 F5 or EF5 tornadoes, the top of the scale.
The deadliest tornadoes in Illinois
| Date | Rating | Deaths in Illinois | Counties |
|---|---|---|---|
| April 21, 1967 | F4 | 33 | Cook County |
| August 28, 1990 | F5 | 29 | Kendall County, Will County |
| April 21, 1967 | F4 | 24 | Boone County, McHenry County |
| December 18, 1957 | F4 | 11 | Franklin County, Jackson County, Williamson County |
| May 29, 1982 | F4 | 10 | Williamson County |
| April 20, 2004 | F3 | 8 | LaSalle County, Putnam County |
| February 29, 2012 | EF4 | 8 | Gallatin County, Saline County |
| February 25, 1956 | F4 | 6 | Clinton County, St. Clair County |
| April 11, 1965 | F4 | 6 | Lake County, McHenry County |
| August 21, 1977 | F3 | 6 | Cumberland County, Shelby County |
Counties with the most tornadoes
| County | Tornadoes since 1950 | Per 1,000 sq mi | Strongest |
|---|---|---|---|
| McLean County | 120 | 101 | F3 |
| Will County | 97 | 114 | F5 |
| Sangamon County | 92 | 105 | F4 |
| Cook County | 86 | 90 | F4 |
| Champaign County | 83 | 83 | F4 |
| Macon County | 77 | 131 | F4 |
| Logan County | 70 | 114 | F4 |
| Tazewell County | 69 | 104 | EF4 |
| Vermilion County | 67 | 74 | F4 |
| LaSalle County | 66 | 58 | EF4 |
| Henry County | 64 | 77 | EF2 |
| Madison County | 62 | 83 | EF4 |
| Christian County | 57 | 80 | EF3 |
| Kankakee County | 56 | 82 | F4 |
| St. Clair County | 55 | 82 | F4 |
Big counties collect more tornadoes simply because they are big. By area, the most tornado-dense counties are DuPage County (134 per 1,000 sq mi), Macon County (131 per 1,000 sq mi), Will County (114 per 1,000 sq mi), Logan County (114 per 1,000 sq mi), Sangamon County (105 per 1,000 sq mi).
Every county in Illinois
Staying safe
When a tornado warning is issued, act at once. Go to a basement, storm shelter or safe room. With none, use a small windowless room on the lowest floor, as far from outside walls as you can, and cover your head and neck. Mobile homes and cars are not safe places to ride out a tornado: leave early for a sturdy building or shelter. Read the full tornado safety guide and the National Weather Service advice linked below.
Sources
- NOAA Storm Prediction Center: Severe Weather Database, tornadoes 1950 to 2024 (public domain)
- NOAA Storm Prediction Center: The Enhanced Fujita Scale (EF scale)
- National Weather Service: Tornado safety
Sources last checked 1 November 2026.
Frequently asked questions
How many tornadoes does Illinois get a year?
About 40 on average from 1950 to 2024; recent years run higher because weak tornadoes are better detected.
When is tornado season in Illinois?
May has had the most. Spring and early summer bring most of them.
What was the deadliest tornado in Illinois?
April 21, 1967: 33 deaths in Illinois.