Excessive Heat in Minnehaha, South Dakota

Dangerous heat index readings reached afternoon peaks as high as 111 degrees at Sioux Falls and 5 miles west-southwest of Sioux Falls, 109 degrees near Colton and Baltic, and 105 degrees 3 miles north-northwest of Sioux Falls.

A large high pressure system parked over the Mississippi River Valley, bringing several days of hot, southerly flow across the region. From the afternoon of June 28 to the evening of June 29, the combination of heat and humidity, boosted by recent rain, created dangerous conditions. Some heat index values exceeded 105 to 110 degrees in and near northwest Iowa.