UV rays are weaker in winter, but are still present. If you care about preventing sun damage and visible aging, daily sunscreen is the absolute number one way. Check out Biore UV Aqua Rich Watery SPF 50 + / PA ++++ or Isntree Hyaluronic Acid Watery Sun Gel. I am super acne prone and I can wear these sunscreens daily and not break out. They also feel super light on the skin and don't make you look oily or leave a white cast. You can buy them in bulk sets to save money as well.