By Cathleen Case, N.P.
Division of Dermatology

When you are outdoors on a cloudy day, it may be tempting to skip the sunscreen, but that would be a mistake. Clouds only partially block the invisible UV rays that cause sunburn and skin damage and a surprising amount gets through. That’s the reason you can still get a sunburn on a cloudy day.

It is estimated that over 90% of ultraviolet (UV) rays can pass through a light cloud cover. So you should still try to protect your skin just like you would on a sunny day. Sunburn, of course, is not the only danger. Prolonged exposure to UV light (as well as bad sunburns) are linked to higher incidences of skin cancer as well as skin aging. Keep in mind that tanned skin is a sign of skin injury and damage. The damage builds and accumulates with continued tanning of the skin. Just like sunburns, tanning increases aging of the skin and the risk of skin cancer including dangerous malignant melanoma.

The best way to protect yourself from the sun is wearing a broad-brimmed hat and clothing that is SPF-rated. Use a broad-spectrum sunscreen on your skin that is SPF 30 or greater and reapply every two hours. Avoiding being outdoors in the sun when UV light is strongest between 10:00am and 4:00pm is also a great way to protect yourself. When swimming or sweating are anticipated, water-resistant sunscreens should be used. Having regular skin cancer check-ups is also a great idea especially if you are fair-skinned. You can learn more about preventing skin cancer here.