Counties with the most tornadoes in Iowa
It's been a busy year for tornadoes in the U.S. According to the National Oceanic and Atmospheric Administration, as many as 1,155 twisters have touched down across the country since the start of the year, above the average for this time of year.
A single day can drive up tornado counts. March 31, 2023, accounted for 163 tornadoes across the Midwest and South. Tornado activity usually peaks in the spring and early summer, and the pace of tornadoes usually slows around late summer. A smaller-scale second tornado season emerges in the fall, mostly in the Gulf Coast states.
Stacker used data from NOAA's National Centers for Environmental Information to find the counties in Iowa that have experienced the most tornadoes since 2000. While data is available going back to 1950, tornado tracking by the National Weather Service became more robust and accurate in the 1990s. Since counties can vary in size, they are ranked by the number of tornadoes per 100 square miles. Counties that experienced less than five tornadoes are not included.
The counties that encounter the most tornadoes aren't all in the infamous Tornado Alley. When adjusted for county area, the top 10 counties that experienced the most tornadoes since 2000 are from nine different states, all in the Southeast with the exception of Cleveland County, Oklahoma.
Research has shown that Tornado Alley is shifting due to warming temperatures fueled by climate change. In the future, the Southeast could become the region that receives the bulk of the country's tornadoes. It's a concerning trend as the South is more populated than the Great Plains and has a higher concentration of mobile homes than other parts of the country, making the storms potentially deadlier and costlier.
As of August 2023, 75 people have died from tornadoes this year, and over 60% of those deaths occurred in mobile homes.
The best way to stay protected during tornadoes is to have multiple ways of receiving storm updates including social media, radio, television, and sirens, and to immediately seek shelter in a basement or interior room without windows when a tornado watch escalates to a warning.
Read on to see which counties experience the most tornadoes in Iowa.
#50. Mahaska County
- #663 nationally
- Tornadoes this year, as of May 31: 0
#49. Van Buren County
- #639 nationally
- Tornadoes this year, as of May 31: 0
#48. Lee County
- #631 nationally
- Tornadoes this year, as of May 31: 0
#47. Poweshiek County
- #620 nationally
- Tornadoes this year, as of May 31: 1
#46. Franklin County
- #612 nationally
- Tornadoes this year, as of May 31: 0
#45. Woodbury County
- #611 nationally
- Tornadoes this year, as of May 31: 0
#44. Tama County
- #600 nationally
- Tornadoes this year, as of May 31: 0
#43. Buena Vista County
- #595 nationally
- Tornadoes this year, as of May 31: 3
#42. Adair County
- #584 nationally
- Tornadoes this year, as of May 31: 0
#41. Lyon County
- #549 nationally
- Tornadoes this year, as of May 31: 0
#40. Wright County
- #536 nationally
- Tornadoes this year, as of May 31: 0
#39. Muscatine County
- #510 nationally
- Tornadoes this year, as of May 31: 1
#38. Mills County
- #509 nationally
- Tornadoes this year, as of May 31: 0
#37. Calhoun County
- #501 nationally
- Tornadoes this year, as of May 31: 2
#36. Carroll County
- #500 nationally
- Tornadoes this year, as of May 31: 0
#35. Humboldt County
- #497 nationally
- Tornadoes this year, as of May 31: 0
#34. Adams County
- #473 nationally
- Tornadoes this year, as of May 31: 0
#33. Delaware County
- #458 nationally
- Tornadoes this year, as of May 31: 2
#32. Sioux County
- #452 nationally
- Tornadoes this year, as of May 31: 0
#31. Jasper County
- #441 nationally
- Tornadoes this year, as of May 31: 0
#30. Cerro Gordo County
- #433 nationally
- Tornadoes this year, as of May 31: 0
#29. Butler County
- #390 nationally
- Tornadoes this year, as of May 31: 0
#28. Clinton County
- #378 nationally
- Tornadoes this year, as of May 31: 2
#27. O'Brien County
- #375 nationally
- Tornadoes this year, as of May 31: 0
#26. Marshall County
- #374 nationally
- Tornadoes this year, as of May 31: 0
#25. Guthrie County
- #353 nationally
- Tornadoes this year, as of May 31: 0
#24. Johnson County
- #346 nationally
- Tornadoes this year, as of May 31: 5
#23. Black Hawk County
- #316 nationally
- Tornadoes this year, as of May 31: 0
#22. Madison County
- #309 nationally
- Tornadoes this year, as of May 31: 0
#21. Greene County
- #286 nationally
- Tornadoes this year, as of May 31: 1
#20. Osceola County
- #273 nationally
- Tornadoes this year, as of May 31: 0
#19. Union County
- #269 nationally
- Tornadoes this year, as of May 31: 0
#18. Pocahontas County
- #264 nationally
- Tornadoes this year, as of May 31: 5
#17. Warren County
- #255 nationally
- Tornadoes this year, as of May 31: 2
#16. Clay County
- #253 nationally
- Tornadoes this year, as of May 31: 0
#15. Linn County
- #246 nationally
- Tornadoes this year, as of May 31: 2
#14. Jones County
- #233 nationally
- Tornadoes this year, as of May 31: 1
#13. Polk County
- #202 nationally
- Tornadoes this year, as of May 31: 0
#12. Benton County
- #201 nationally
- Tornadoes this year, as of May 31: 3
#11. Story County
- #175 nationally
- Tornadoes this year, as of May 31: 0
#10. Dallas County
- #168 nationally
- Tornadoes this year, as of May 31: 0
#9. Howard County
- #166 nationally
- Tornadoes this year, as of May 31: 0
#8. Boone County
- #150 nationally
- Tornadoes this year, as of May 31: 0
#7. Grundy County
- #142 nationally
- Tornadoes this year, as of May 31: 2
#6. Scott County
- #140 nationally
- Tornadoes this year, as of May 31: 1
#5. Hardin County
- #89 nationally
- Tornadoes this year, as of May 31: 0
#4. Marion County
- #79 nationally
- Tornadoes this year, as of May 31: 7
#3. Hamilton County
- #77 nationally
- Tornadoes this year, as of May 31: 0
#2. Buchanan County
- #70 nationally
- Tornadoes this year, as of May 31: 2
#1. Webster County
- #64 nationally
- Tornadoes this year, as of May 31: 0