It has been a rainy summer, like it should be... but they are afternoon showers, they last for a couple hours, if that and then are gone.. usually.
They certainly wont ruin your trip, they are part of what makes florida, florida... Some wicked lightning, the rumbling thunder, a heavy shower for awhile.. then its gone, its part of the adventure, the excitement of life in florida.
And it really does help with the heat, ya know, it does get yucky hot here at times, that afternoon shower can change the day if it lasts long enough to cool off the world. You'll see.
Tell dh not to worry bout it, you guys will love it.. You can use that downtime for indoor kinda things.