Excessive Heat in Hamlin, South Dakota

High heat and humidity returned to the region on July 26th. A high temperature of 105 degrees was recorded by the South Dakota State University mesonet station 7 miles southwest of Hayes, with a 104 degree reading recorded 2 miles south southwest of Fort Pierre. Heat and humidity combined for heat index values to top out at 113 degrees at a mesonet station run by the Wakpala public school, while a peak heat index value of 112 was recorded 3 miles southwest of Onaka. 23 additional weather stations would go on to record a peak heat index value of 105 degrees or higher on July 26th. On July 27th, the heat and high humidity conditions continued with high temperatures over 100 degrees across mainly central South Dakota. A peak heat index value of 118 degrees was recorded at a mesonet station in Mellette, with the Automated Weather Observing System located at the Redfield Municipal Airport recording a peak heat index value of 117. An additional 38 weather stations would record a heat index in excess of 105 degrees that afternoon.