The unusually warm weather for September in some parts of the country may have taken your focus off the fact that it’s technically fall, but your skin will notice the difference. Your No. 1 enemy remains the sun. “We educate patients that UltraViolet A, the ray that passes through glass and windows, is present every day—even on non-sunny days, and penetrates the skin deeper than UVB rays causing DNA damage (skin cancer) and destroying collagen and elastin (wrinkles),” Dr. Adean Kingston, cosmetic dermatologist, says. You probably know that you should try to avoid pollution as best as possible, stop smoking, and refrain from tanning of any kind, and that includes sunbathing and tanning beds, Dr. Kingston adds.