Iowa recorded 3,031 tornadoes from 1950 through 2024, an average of 40 a year, in NOAA’s Storm Prediction Center database. They killed 98 people. The busiest year was 2024, with 126.
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 Iowa
June is the peak, with 779 tornadoes since 1950 (26% of the total).
How strong
| Rating | Estimated 3-second gust | Tornadoes |
|---|---|---|
| F0 / EF0 | Light damage: 65 to 85 mph (EF scale) | 1,268 |
| F1 / EF1 | Moderate: 86 to 110 mph | 958 |
| F2 / EF2 | Considerable: 111 to 135 mph | 494 |
| F3 / EF3 | Severe: 136 to 165 mph | 121 |
| F4 / EF4 | Devastating: 166 to 200 mph | 48 |
| F5 / EF5 | Incredible: over 200 mph | 6 |
| EF-U | Unknown: no damage to rate (mostly since 2016) | 136 |
Iowa has had 6 F5 or EF5 tornadoes, the top of the scale.
The deadliest tornadoes in Iowa
| Date | Rating | Deaths in Iowa | Counties |
|---|---|---|---|
| May 15, 1968 | F5 | 13 | Butler County, Chickasaw County, Floyd County, Franklin County, Howard County |
| May 25, 2008 | EF5 | 9 | Black Hawk County, Butler County, Grundy County |
| October 14, 1966 | F5 | 6 | Wright County |
| September 16, 1978 | F3 | 6 | Jasper County, Marshall County, Poweshiek County |
| March 5, 2022 | EF4 | 6 | Jasper County, Madison County, Polk County, Warren County |
| May 15, 1968 | F5 | 5 | Fayette County |
| May 21, 2024 | EF4 | 5 | Adair County, Adams County, Taylor County |
| June 11, 2008 | EF3 | 4 | Harrison County, Monona County |
| June 28, 1979 | F4 | 3 | Calhoun County, Pocahontas County |
| April 16, 1967 | F3 | 2 | Van Buren County |
Counties with the most tornadoes
| County | Tornadoes since 1950 | Per 1,000 sq mi | Strongest |
|---|---|---|---|
| Polk County | 70 | 118 | EF4 |
| Scott County | 67 | 144 | F4 |
| Story County | 65 | 114 | F5 |
| Linn County | 63 | 87 | F4 |
| Dallas County | 60 | 102 | F4 |
| Webster County | 59 | 82 | F4 |
| Woodbury County | 57 | 65 | EF4 |
| Boone County | 56 | 98 | F5 |
| Pottawattamie County | 56 | 58 | F4 |
| Clinton County | 55 | 77 | F4 |
| Plymouth County | 52 | 60 | F3 |
| Warren County | 50 | 87 | EF4 |
| Sioux County | 50 | 65 | F3 |
| Buchanan County | 49 | 86 | EF3 |
| Pocahontas County | 49 | 85 | EF4 |
Big counties collect more tornadoes simply because they are big. By area, the most tornado-dense counties are Scott County (144 per 1,000 sq mi), Polk County (118 per 1,000 sq mi), Story County (114 per 1,000 sq mi), Dallas County (102 per 1,000 sq mi), Boone County (98 per 1,000 sq mi).
Every county in Iowa
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 Iowa 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 Iowa?
June has had the most. Spring and early summer bring most of them.
What was the deadliest tornado in Iowa?
May 15, 1968: 13 deaths in Iowa.