After a few cold nights and some wind, I figured I go see what was up, and how bad water temps were on Murray. I had 78.5-80 at 9-10 AM. My goal was two-fold in that I just rigged my boat for deep water trolling, and wanted to play around with the downriggers, and make sure some rods I already had would work with them. It was a successful day testing new equipment, with basically no effort catching fish.
I would say that the temps that high in the morning is a sign that it's probably done for a while.