Here's the really interesting part: "UVA rays are the same all year round," says Graf. That means even when it's cloudy in January, UVA rays are wrinkling your skin. The moral of the story: wear sunscreen every day, all year long. Graf likes Glytone Sunscreen Lotion SPF 40, $32, which give broad spectrum protection with both chemical and physical SPF ingredients.
SEE NEXT PAGE: Fact: You don't need sun exposure to get Vitamin D.