If I went to the Niagara Region in January, the outdoor pools there would be used for hockey, even though there are pool heaters available !! The past 17 days here in central Fla, we have had temps over 100, with heat indexes around 105 to 107. Any pool exposed to the searing heat & sunshine is going to be warm. That's just the way it is. Heck....even the water from our cold water taps is luke-warm!!
I always tell people that lifestyles are seasonally reversed here in Fla. We cannot live without A/C in the summer, and the northerners cannot live without heat in the winter.
I'm not trying to be mean or sarcastic, but that's just the way it is in Florida from June through September. That's why I wish I could become a snowbird and go back north (I'm from your area originally bgula) for the summer. My employers think differently.