Folks, the weather report is in, and the temps, they are a-risin'! It's officially time to break out the Birkenstocks (and the rosé, while you're at it) and place your brisk-weather gear into off-season hibernation. But wait! Leave those long-sleeved button-ups where they hang. With a quick little tie at the waist, those babies are suddenly summer-perfect. Get inspired by these celebs, and don the look this season.