I started my solar system for this swim season and it has peaked at around 75ºF as the weather has been a little inconsistent. The following is the minimum/maximum/average air temperature and end-of-day water temperature.
........... <----- Air ------>
Date .... Min. ... Max. ... Avg. .. Water
3/22 ... 41.9 ... 54.5 ... 47.2 ... 57 ... Start before solar turned on
3/23 ... 40.3 ... 59.2 ... 48.4 ... 59 ... solar started in afternoon
3/24 ... 33.6 ... 66.6 ... 49.3 ... 62
3/25 ... 35.5 ... 69.2 ... 51.8 ... 65
3/26 ... 43.0 ... 70.7 ... 57.5 ... 69
3/27 ... 43.4 ... 77.9 ... 58.2 ... 72
3/28 ... 41.4 ... 70.3 ... 56.2 ... 74
3/29 ... 47.4 ... 64.0 ... 55.2 ... 75
I have an opaque electric safety cover so don't get the benefit of a clear bubble-type solar cover which would not only heat more during the day but also lose less heat at night. Even so, the water temp gets to around 20ºF higher than the average air temp. In the peak of the summer when the sun's heating is more intense, I get around 25ºF higher than the average air temp.
Richard
........... <----- Air ------>
Date .... Min. ... Max. ... Avg. .. Water
3/22 ... 41.9 ... 54.5 ... 47.2 ... 57 ... Start before solar turned on
3/23 ... 40.3 ... 59.2 ... 48.4 ... 59 ... solar started in afternoon
3/24 ... 33.6 ... 66.6 ... 49.3 ... 62
3/25 ... 35.5 ... 69.2 ... 51.8 ... 65
3/26 ... 43.0 ... 70.7 ... 57.5 ... 69
3/27 ... 43.4 ... 77.9 ... 58.2 ... 72
3/28 ... 41.4 ... 70.3 ... 56.2 ... 74
3/29 ... 47.4 ... 64.0 ... 55.2 ... 75
I have an opaque electric safety cover so don't get the benefit of a clear bubble-type solar cover which would not only heat more during the day but also lose less heat at night. Even so, the water temp gets to around 20ºF higher than the average air temp. In the peak of the summer when the sun's heating is more intense, I get around 25ºF higher than the average air temp.
Richard