List of Iowa tornadoes

The U.S state of Iowa experiences multiple tornadoes every year. There have been at least 3,422 recorded tornadoes since 1950. At least 2,340 people have been injured, and 100 people have died due to these tornadoes.^[1] There have been multiple tornadoes before 1950, but most of them are not recorded accurately or at all, but the most violent and deadliest tornadoes before 1950 have been recorded. The deadliest tornado was the Camanche tornado, which killed 72 people in Iowa.^[2]

2024 was a record-breaking year in Iowa. Iowa saw 125 tornadoes in 2024 which beat the previous record of 120 tornadoes in 2004. In April and May alone, Iowa saw 98 tornadoes, giving the months of April 2024 and May 2024 the second and third most tornadoes in a month, just before May 2004 which saw 57 tornadoes.^[3]

The most tornado-prone parts of Iowa are in the northeastern counties. The counties of Delaware, Black Hawk, Buchanan, Linn, and Benton on average have seen at least one strong tornado each year from 1953 to 2008.^[4]

Climatology

A tornado is a violent column of air that extends from a thunderstorm to the ground. Although tornadoes can happen at any time of the year, the most popular time for tornadoes to form in Iowa is early in the spring.^[5] Iowa is in the central plains, where the Rocky Mountains to the west and the Appalachian Mountains to the east meet. This unique geography creates a funneling effect, channeling warm, moist air from the Gulf of Mexico and cool, dry air from Canada.^[6] These are the most ideal conditions for tornadoes to form, with Iowa being caught inside of Tornado Alley, along with other Great Plains states, greatly increasing the chances of a tornado to form in Iowa.^[7]

Intense tornadoes

The Enhanced Fujita Scale, or EF Scale, is used to assign a tornado a rating based on estimated wind speeds and related damage. When tornado-related damage is surveyed, it is compared to a list of damage indicators and degrees of damage, which help estimate better the range of wind speeds the tornado likely produced. From that, a rating from EF0 to EF5 is assigned.^[9] From 1974 to 2007, the Fujita Scale was used to calculate the strength of a tornado.^[10] This system had calculated the strength based on the damage delt to well-built wooden homes.^[11] Tornadoes recorded before 1974 were examined and rated accordingly. Multiple flaws including a lack of damage indicators, difference in opinion from evaluators, and no calibration of damage with relation to wind speed caused researchers from Texas Tech University to re-examine and re-do the Fujita Scale. A group of wind data experts met in 2001 and came up with 28 new damage indicators which included poles, trees, and other buildings other than just wooden frame homes. After discussion, the National Weather Service officially adopted the new scale in 2007.^[12]

Pre-1900

A total of 142 recorded tornadoes touched down in Iowa before 1900. At least 540 people died and 2,186 people were injured due to these tornadoes before 1900. There have been 63 intense tornadoes with a rating of F3+, the deadliest of which was on June 3, 1860, in Camanche, killing 92. This time period for tornadoes in Iowa is the deadliest period of tornadoes in Iowa, with each recorded tornado killing on average 3.48 people. The first use of a tornado warning in the United States wasn't until March 25, 1948.^[13] This caused tornadoes before the 1950s to be more dangerous, because people thought that tornadoes would be too rare to strike a region so there was no point in issuing warnings.^[14]

Camanche Tornado

On June 3, 1860, an F4 tornado touched down north of Bennett, moving across eastern Iowa, killing 20 people in rural Clinton County. It then ripped through Camanche, destroying almost every building in the town and killing 41. A raft carrying 26 was hit by the tornado and flipped, killing all but 3 men. The tornado caused an estimated $250,000 - $300,000 in damages.^[15]

Grinnell Tornado

On June 17, 1882, two tornadoes formed and intersected in Grinnell forming one tornado at F5 intensity.^[16] It travelled across central Iowa, killing a total of 68 people. 10 people died near Rippey, 7 people died in Jasper County, 39 in Grinnell, and 10 in Malcolm.^[17]

Pomeroy Tornado

On July 6, 1893, an F5 tornado touched down northwest of Quimby, moving toward the town of Pomeroy. With a damage path 500 yards (460 m) wide and 55 miles (89 km) long, the tornado destroyed about 80% of the homes in Pomeroy. The tornado killed 71 people and injured 200.^[18]

1900–1949

A total of 338 tornadoes touched down in Iowa between 1900 and 1949. At least 292 people died and 1,861 people were injured. There were 75 intense F3+ tornadoes, the deadliest of which was the 1913 Easter tornado that hit Omaha, Nebraska, making its way over the border into Iowa, killing a total of 103 people and injuring 350 others.^[20]

Omaha Easter Sunday Tornado

An F4 tornado touched down in La Vista, Nebraska, a suburb of Omaha, traveling through the city of Omaha and crossing the border into Iowa. In total, 103 people died, 9 of whom were in Iowa.^[21] The tornado had a damage path of 40.3 mi (64.86 km) long and 400 yds (365.76 m) wide.^[22]

Crawford County Tornado

On May 21, 1918, an F5 tornado touched down in Crawford County, moving across the county and into Greene County as well. According to witnesses, twenty or more farms were destroyed and a couple riding in a buggy north of Churdan were caught by the tornado and died. Mattresses were carried two miles away and farms and homes were wiped completely off their foundations.^[23]

1950–present

A total of 3,118 recorded tornadoes have touched down in Iowa since 1950, causing 101 deaths and injuring 2,400 as of July 2025. There have been 20 (E)F5 tornadoes, or 2 or more fatalities, the deadliest being the 1968 Hansell-Charles City tornado, which killed 13 and injured 462.^[25]

1968 Hansell-Charles City tornado

On May 15, 1968, a multi-vortex tornado hit the communities of Hansell, Hampton, Charles City, Elma, and Aredale, all in Iowa. It killed 13, injured 462, and hundreds of buildings were destroyed, primarily in the town of Charles City. Damage estimates were of more than $20 million. All of the deaths occurred in Charles City.^[26]

2008 Parkersburg-New Hartford tornado

On the afternoon of May 25, 2008, as part of a large tornado outbreak across the central plains, a large and extremely powerful EF5 wedge tornado devastated the towns of Parkersburg and New Hartford. The tornado killed nine people and caused about $75 million in damages in its approximately 43 mile path across northeast Iowa. The tornado killed 7 in Parkersburg and 2 in New Hartford.^[27][28]

2024 Greenfield tornado

On the afternoon of May 21, 2024, a violent tornado tracked across southwestern Iowa, devastating the city of Greenfield. The tornado destroyed many structures and wind turbines across its path that stretched through Page, Taylor, Adams, and Adair counties, while also causing more than $31 million in property damage, killing five people and injuring 35 more. All of the fatalities happened in the town of Greenfield.^[29] A Doppler on Wheels estimated wind speeds of 309–318 mph (497–512 km/h), the third highest wind estimate from inside a tornado in the United States, before the 2013 El Reno tornado and the Bridge Creek tornado.^[30]

Notes

1. ^ Grazulis classifies an intense tornado as a tornado rated F3 or higher.
2. ^ Grazulis rated this tornado an F4, but other sources, including the National Weather Service have rated this tornado an F5

References

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3. ^ Cogil, Craig & Hagenhoff, Brooke. "Iowa Tornadoes 2024". National Weather Service. Archived July 9, 2025 at the Wayback Machine. Retrieved July 9, 2025.
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5. ^ "Severe Weather 101 - Tornadoes". National Oceanic and Atmospheric Administration. Archived 2025-09-26 at the Wayback Machine. Retrieved 2025-09-29.
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7. ^ Kirkland, Kyle (2010). Weather and Climate: Notable Research and Discoveries. Infobase Publishing. ISBN 978-0-8160-7446-4.
8. ^ Cogil, Craig (2019). "Iowa Tornado Climatology 1980-2019". Archived April 28, 2025 at the Wayback Machine. Retrieved February 22, 2025.
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10. ^ Fujita, Tetsuya Theodore (1970). ""Proposed Characterization of Tornadoes and Hurricanes by Area and Intensity," by Fujita, T. Theodore; SMRP Research Paper Number 91, 1970.". Department of the Geophysical Sciences, University of Chicago, Chicago, Illinois, USA. hdl:10605/261875
11. ^ Collins, Jennifer M.; Rohli, Robert V.; Paxton, Charles H. (2017-09-19). Florida Weather and Climate: More Than Just Sunshine. University Press of Florida. ISBN 978-0-8130-5288-5.
12. ^ Hangan, Horia & Kareem, Ahsan (2021). The Oxford Handbook of Non-Synoptic Wind Storms. Oxford University Press. ISBN 978-0-19-067025-2.
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14. ^ Giaimo, Cara (2016-02-10). "Until 1950, U.S. Weathermen Were Forbidden From Talking About Tornados". Atlas Obscura. Retrieved 2025-09-30.
15. ^ "The Terrible Tornado.; The towns of Camanche, Iowa, and Albany, Ill. entirely destroyed from thirty to fifty persons killed, and one hundred wounded.". The New York Times-US. June 7, 1860. ISSN 0362-4331. Archived May 14, 2025 at the Wayback Machine. Retrieved May 12, 2025.
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17. ^ Kelley, Matt (June 17, 2016). "Iowa's worst tornado days 134 years ago remembered". Radio Iowa-US. Archived May 14, 2025 at the Wayback Machine. Retrieved May 13, 2025.
18. ^ Grazulis, T. P. (1990). Significant Tornadoes: A chronology of events. Tornado Project. ISBN 978-1-879362-02-4.
19. ^ Grazulis, T. P. (1990). Significant Tornadoes: A chronology of events. Tornado Project. pp. 1–83. ISBN 978-1-879362-02-4.
20. ^ Meyer, Joseph (2023-03-24). "Easter Sunday 1913 Tornadoes - Part 4 | The Omaha Tornado". KMTV 3 News Now Omaha. Archived July 15, 2025 at the Wayback Machine. Retrieved 2025-07-15.
21. ^ Bulletin of the American Geographical Society. American Geographical Society. 1914.
22. ^ "Easter came early in 1913, Omaha Tornado". National Weather Service-US. July 15, 2025. Archived July 15, 2025 at the Wayback Machine. Retrieved 2025-07-15.
23. ^ (July 1993). Significant Tornadoes 1680–1991: A Chronology and Analysis of Events. St. Johnsbury, Vermont: The Tornado Project of Environmental Films. ISBN 1-879362-03-1.
24. ^ Grazulis, T. P. (1990). Significant Tornadoes: A chronology of events. Tornado Project. pp. 86–343. ISBN 978-1-879362-00-0.
25. ^ Commodari, Robbie (2024-05-15). "The tornado outbreak of May 15, 1968". KWWL. Archived July 15, 2025 at the Wayback Machine. Retrieved 2025-07-15.
26. ^ "May 15 1968 Iowa Tornado Summary". National Weather Service-US. Archived May 14, 2025 at the Wayback Machine. Retrieved February 21, 2025.
27. ^ Marshall, Timothy; Jungbluth, Karl; Baca, Abigail (March 3, 2016). "The Parkersburg, IA Tornado: 25 May 2008". Archived March 3, 2016 at the Wayback Machine. Retrieved February 20, 2025.
28. ^ Riley, Roger (2024-06-19). "Parkersburg traveled a long road to recovery after EF-5 tornado". WHO-US. Archived 2024-06-20 at the Wayback Machine. Retrieved 2025-07-15.
29. ^ Mendiola, José. "Greenfield tornado damaged, destroyed at least 153 Iowa homes in roughly one minute". The Des Moines Register-US. Archived May 14, 2025 at the Wayback Machine. Retrieved February 21, 2025.
30. ^ Satre, Zane (June 26, 2024). "300+ mph: Greenfield, Iowa tornado had some of the strongest winds ever recorded, radar data shows". Cowles Communications. Archived May 8, 2025 at the Wayback Machine. Retrieved February 21, 2025.
31. ^ Grazulis, T. P. (1990). Significant Tornadoes: A chronology of events. Tornado Project. pp. 352–682. ISBN 978-1-879362-00-0.
32. ^ "Storm Events Database - Search Page | National Centers for Environmental Information". National Oceanic and Atmospheric Administration. Retrieved 2025-09-30.
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