Temperatures reaching as high as 102 degrees have set records in several western and northern cities.
The Des Moines Sioux Center's 102 broke a 32-year-old record for Aug. 30. Sioux City and Orange City also hit 102 on Thursday.
The 99 in Mason City broke the record of 95 set in 1941, and Waterloo reached a record-tying 96 degrees.
Meteorologists say the low humidity that accompanied the heat made the high temperatures more tolerable for many people.