Iowa has averaged 46 tornadoes a year since 1980, according to a review of tornado data by Craig Cogil of the National Weather Service.
And what is the peak time for a tornado?
4 p.m. to 5 p.m. on a June day.
Cogil is a meteorologist in the weather service office that serves Des Moines and central Iowa.
June is the peak month for tornadoes, and 4 p.m. to 5 p.m. is the peak hour.
Cogil said tornadoes are most likely to occur in the late afternoon because the daylong warming effect of the sun, combined with moisture in the atmosphere, provides much of the energy to produce tornadoes.
As is the case elsewhere, most of Iowa's tornadoes have been of lesser strength. About 86 percent are estimated to have had wind speeds of 65 to 110 mph, ranking them as EF0 and EF1.
Source: National Weather Service/Des Moines