I live in South Dakota, and can tell you late August is not cooler. The nights might be, but not the day times. 89 degrees here at 1:32am last night. I am in the SW part of the state and our forecast for the next few days is 15 to 25 degrees cooler than it has been. We have had extremely dry conditions. Fire danger is beyond extreme. Many parts of western South Dakota have gone to banning almost every type of open flame (including smoking outside of a building or vehicle).

I hope you find your stay and hunting in South Dakota a pleasure. Welcome to the state of Great Faces and Great Places.