I'll let some more experienced people answer your question better, but I'd say the extreme heat caused blossom drop.

Agree, blossom drop is common when there is excess nitrogen fertilizers used but especially when there are high temps (there is a detailed FAQ here about Blossom Drop) and many other discussions if you search 'blossom drop'.

Summer isn't tomato growing time in Florida - in the north yes, but not in Florida. And that may well be your problem. Early spring and late fall is the tomato season according to all the Florida gardeners. It is simply too hot and humid in the summer for the plant to set fruit.

Dave

Here is a link that might be useful: FAQ: Blossom Drop