It's currently 86, but with some colder nights and highs only in the 70's and low 80's i'm sure it gonna go down to about 80. When we were filling it up we put the solar cover on it and had 82 degree water when we finished, haven't looked back, we actually hit 94 a few weeks ago when the temps were over 100 for a few days. Next year is a 4x20 solar panel on the garage roof and a deck if the building inspector lets me get away with a few variances.