If it follows the usual pattern, it will be hot and muggy all morning, thundershower in the afternoon, and then get cooler and pleasant towards evening.
The first time I saw a Florida summer forecast for our vacation week, I cried like a baby thinking our whole trip was ruined. Turned out it really only rained while we were at our resort napping anyway! Good luck to you!
I lived in Orlando for a year and a half, and during the summer there would be a cloudburst in the afternoon, but the rest of the day was fine. Only lasted from 10 to 20min