i lived in gainesville for a few years and even though farther north than fort lauderdale, summers weren't any cooler. if i remember right the days were often hazy, rather than the mostly clear blue skies we enjoy down here. also the humidity mid-state can get to you. staying along the coasts will get you at least a seabreeze most of the time (though you need to be within a few miles of the ocean or gulf).
when we lived even closer to the equator, on st. croix, usvi, summer didn't seem as brutal there as florida, possibly because of being deeper into the trade winds. tough for me to judge because i was so much younger when the heat didn't effect me as much. in any case, the further north in florida, the less the effect of the trades and of course inland, no seabreeze either so the air & humidity stagnate, especially in summer.
south florida summers aren't so bad as long as you go from your airconditioned house to the a/c'd car to the a/c'd gym or, yikes, mall, and then into the pool. i find the ocean water near shore too warm to enjoy in the middle of summer but the swim hall of fame "air conditions" their pool by spraying the water into the air at night.
we even have less extreme hot days than some of the country in summer and we are equipped to handle the heat. sure would be nice though if summer nights brought a little relief. nothing worse than going out at 9 pm only to break a sweat.
where ever you decide, bring lots of t-shirts.
