F0/EF0 1 2 3 4 5 · Lines run from where each tornado touched down to where it lifted; dots are short paths. Neighboring counties are outlined.
When tornadoes hit Calhoun County
May has brought the most, 15 of 40. About 68% touched down between 2 pm and 8 pm (Central Standard Time, as the Storm Prediction Center records it).
By decade
More tornadoes in recent decades mostly reflects better detection and reporting (Doppler radar, storm spotters, damage surveys), especially for weak EF0 tornadoes, not necessarily more storms. The 2020s bar covers only 2020 to 2024.
How strong they were
| Rating | Estimated 3-second gust | Tornadoes |
|---|---|---|
| F0 / EF0 | Light damage: 65 to 85 mph (EF scale) | 16 |
| F1 / EF1 | Moderate: 86 to 110 mph | 8 |
| F2 / EF2 | Considerable: 111 to 135 mph | 6 |
| F3 / EF3 | Severe: 136 to 165 mph | 2 |
| F4 / EF4 | Devastating: 166 to 200 mph | 4 |
| F5 / EF5 | Incredible: over 200 mph | 0 |
| EF-U | Unknown: no damage to rate (mostly since 2016) | 4 |
Tornadoes before February 2007 were rated on the original Fujita (F) scale; since then the National Weather Service uses the Enhanced Fujita (EF) scale. Wind speeds above are EF-scale estimates from damage, not measurements. See what the EF scale means.
The strongest tornadoes in Calhoun County
| Date | Rating | Path length | Path width | Deaths | Injuries |
|---|---|---|---|---|---|
| June 28, 1979 | F4 | 14.9 mi | 33 yd | 3 | 26 |
| June 9, 1954 | F4 | 9.9 mi | 440 yd | 1 | |
| May 5, 1965 | F4 | 9.9 mi | 200 yd | ||
| May 27, 1995 | F4 | 36 mi | 400 yd | ||
| June 7, 1953 | F3 | 30.7 mi | 200 yd | ||
| July 14, 2021 | EF3 | 10.8 mi | 505 yd | ||
| August 5, 1958 | F2 | 27.1 mi | 60 yd | ||
| May 15, 1965 | F2 | 0.5 mi | 50 yd | ||
| April 26, 1984 | F2 | 22 mi | 200 yd | ||
| July 28, 1986 | F2 | 4 mi | 150 yd |
Deaths and injuries are for each tornado’s whole path, which can cross other counties.
The deadliest
The deadliest tornado to touch Calhoun County was an F4 on June 28, 1979. It killed 3 people and injured 26 along its 14.9-mile path.
Most recent tornadoes
| Date | Rating | Path length | Path width | Deaths | Injuries |
|---|---|---|---|---|---|
| April 16, 2024 | EF-U | 0.6 mi | 30 yd | ||
| April 16, 2024 | EF1 | 5.2 mi | 75 yd | ||
| May 13, 2023 | EF0 | 1.4 mi | 50 yd | ||
| May 13, 2023 | EF-U | 0.6 mi | 30 yd | ||
| December 15, 2021 | EF2 | 18 mi | 80 yd | ||
| December 15, 2021 | EF1 | 19 mi | 100 yd | ||
| December 15, 2021 | EF-U | 1.3 mi | 40 yd | ||
| July 14, 2021 | EF3 | 10.8 mi | 505 yd |
The official database ends with 2024. For storms since then, see the Storm Prediction Center’s reports and your local National Weather Service office.
FEMA’s tornado risk rating
FEMA’s National Risk Index rates the tornado risk in Calhoun County as relatively moderate, with a score of 74 out of 100 compared with every other U.S. county. It estimates about 0.52 tornadoes a year here and an expected annual loss of about $2,754,007 to buildings, people and farming. The index mixes how often tornadoes strike with what is exposed and how well a community can recover, so a busy rural county can rate lower than a less active city.
Neighboring counties
- Webster County, IA: 59 tornadoes
- Pocahontas County, IA: 49 tornadoes
- Carroll County, IA: 32 tornadoes
- Greene County, IA: 32 tornadoes
- Sac County, IA: 27 tornadoes
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)
- FEMA National Risk Index, tornado county data (December 2025 release)
- NOAA Storm Prediction Center: The Enhanced Fujita Scale (EF scale)
- National Weather Service: Tornado safety
Sources last checked 1 November 2026.