0am:The Harrodsburg, IN forecast for Apr 15 is 50 degrees and Partly cloudy. There is 57 percentage chance of rain and 3 mph winds from the South-Southeast. 3am:The Harrodsburg, IN forecast for Apr 15 is 47 degrees and Partly cloudy. There is 64 percentage chance of rain and 3 mph winds from the Southeast. 6am:The Harrodsburg, IN forecast for Apr 15 is 43 degrees and Patchy rain possible. There is 72 percentage chance of rain and 3 mph winds from the Southeast.