Key West

Back down south, Key West can be excellent in the summer as well. The ocean breezes keep the heat down to a more bearable level, and the massive shade trees over a lot of the streets help with that, too. Like Miami, timing a trip to Key West in the summer helps to dodge the crowds.

If you can, get in touch with one of the local companies that do eco-friendly snorkeling tours around the key: the water this time of year tends to be clear and the reefs are some of the most gorgeous in the world.