I guess it all depends on your location Andy and how far are you willing to travel (your budget etc.) but as Sandy pointed out the Caribbean is an excellent place to spend a nice and relaxing vacation you could even get to vist several islands while in there and practice water sports. I also heard that Mexico has incredible tourist palces. Personnely, based on what you wrote, I would definitely recommend heading for a nice beach looking for a refreshing summer-end.
Have a nice and safe trip
!!!
Good look