Florida weather is different - I lived in birmingham, al before moving to Fl - now even being out when it is 60 doesn't even make me cold wear shorts and t-shirts mostly- that say the days in Fl are definitely hotter. when are you planning on swimming - if midnight or later then you might need to get the pool heat - but before then I won't do it. Now if you are planning on swimming in the early morning - then would definitely heat the pool. It seems to be at the coldest early morning from 5:00am until about an hour after the sun comes up. Now if cloudy in the morning make that 2 hours.