Well, my pond has been warmer this year than the last few. It was bouncing between 72 at night and 74 during the day for 3 weeks. One day it spiked to 75 for around 6 hours. The last couple of cool nights now have it 70-71. I would have never thought the trout would have made it through these temps but here they are yesterday chowing down with the kio & bluegills. as far as I can tell, I haven't lost a fish yet.