I agree that pool cover helps a lot. We have an automatic one (which I don’t particularly recommend as it’s prone to breaking at the most inopportune times, and it certainly cuts back evaporation and helps keep in the heat. But I never felt our pool was warm enough except in the hottest parts of the summer. Might depend on where you live. We’re in Pt. Loma, so closer to the coast and colder. And of course, it tends to be more overcast/foggy, which is also a factor for solar heating.
