86 in the CA Central Valley, using a solar cover at night. Despite a 100 degree heat wave, not spiking to the 88/89 that we hit last week in cooler weather. I think the sun angle is changing enough that a tree south of the pool is shading just enough to reduce heat gain. I suspect we don't have much longer, but 86 for daughter's birthday pool party tomorrow isn't bad. Just bought the place this summer, so don't know what to expect, but until I got the cover we were struggling to get to 83/84 even back in August, dropping below 80 at night (it gets hot here, but it also is very cool and clear most nights)