As much as I like Florida and hot weather, I have to agree with Sweet Willie. It's not for everyone, and it helps to be heat-tolerant and already live in a hot humid climate. Getting a sunburn in the first 15 minutes of a vacation sucks bigtime. The sun is a little weaker up north and the temps lower. I'd opt for Cape Cod, Maine coast, Rhode Island, any of the islands (Martha's Vineyard, Nantucket, Block). What's least crowded? Personal favorites would include the outer Cape, Misquamicut, Edgartown and Ogunquit.