If it seems like every day is shorter, colder, and rainier than the day before, well...you’re living in San Francisco. So if you’ve got some unused vacation days, climb out from under the fog and use three of them to spend five exhilarating days in Hawaii. The islands offer relaxation and adventure in equal measure: Sunbathe all day or hike through the jungle, luxuriate at the spa or snorkel with sea turtles. And once night falls, Oahu’s bustling bar and restaurant scene puts a tropical twist on your typical night out.