Winter sun and your skin cancer risk

When the temperature drops or you haven’t seen the sun in days, don’t think you can put away the sunscreen. Even in the winter and on cloudy days, it’s important to guard your skin against cancer and aging.

Why? Harmful ultraviolet (UV) rays are present year-around. They can even filter through dark cloud coverage to reach your skin.

“If you’re outside, any uncovered areas of your body are exposed to UV rays,” says Susan Chon, M.D., associate professor in the Department of Dermatology at MD Anderson. And, the primary cause of skin cancer is too much sun exposure.

More than two million Americans are diagnosed each year with skin cancer, according to the American Cancer Society. This makes it the most common type of cancer in the United States.

The good news: It’s one of the easiest to prevent, including the most serious form, malignant melanoma. Other more common types of skin cancer, such as basal cell and squamous cell carcinomas, are treatable if found early.  

“So, it’s important to wear sunscreen year-around to lower your chances of getting skin cancer,” Chon says.

Learn why the winter sun and cloudy days matter and how to protect your skin.

Rays don’t retreat in winter

During winter, the Earth’s Northern Hemisphere points away from the sun, and the atmosphere blocks some of the sun’s harmful UV rays. Temperatures drop as the sun’s rays are further away.

But don’t let these seasonal effects trick you. If you’re outside, you’re still at risk for skin damage.

"In some southern parts of the United States, the amount of UV radiation from the sun doesn’t drop a lot during winter months,” Chon says. “The sun can be strong regardless of the season or temperature.”

Higher altitude means higher risk

During winter, you’re probably ready to hit the ski slopes. Beware: In high altitudes, UV rays are even more intense. Plus, the risk for sunburn is higher because the thinner atmosphere doesn’t block as many of the sun’s harmful rays.

To make matters worse, snow reflects up to 80% of the sun’s rays. A day on the slopes can do as much damage to your skin as a day on the beach.

“Although you’re on a winter vacation, you can experience a bad sunburn,” Chon says. Just one blistering sunburn increases your skin cancer risk and should be reported to your doctor. Five or more sunburns doubles your risk for melanoma.  “So wear sunscreen even on your winter vacations,” Chon says.

Protect your skin on cloudy days

Don’t let a cloudy day fool you into forgoing sunscreen. Even through cloud coverage, UV rays reach the Earth’s surface and your skin.

Some studies even show an effect called cloud enhancement of UV radiation. The sun’s beams reflect off the sides of clouds causing radiation to be more focused and dangerous. 

So don’t leave your skin out to fry. Protect it even if you can’t see the sun.

Keep up good sunscreen habits

Chon suggests these year-round sunscreen tips:

• Wear sunscreen that’s at least SPF 30, broad spectrum to block both UVA and UVB rays, and water resistant.
• Apply sunscreen liberally to dry skin 30 minutes before going outdoors.
  • Pay extra attention to face, ears, hands and arms.
  • For sensitive areas, use sunscreen with zinc oxide.
• Reapply sunscreen every two hours or immediately after swimming or sweating.

“Applying sunscreen regularly decreases the number of sunburns you get,” Chon says. “This will reduce your skin cancer risks dramatically, even on the most blustery winter days.”

Confused by all the sunscreen choices? Chon says the best product is one you will use – and use often. The FDA’s rules help take some of the mystery out of sunscreen labels.

Enjoy the sun safely

To completely protect your skin in the winter, Chon suggests you take additional steps.

• Use SPF 30 lip balm.
• Cover up with a long-sleeved jacket, hat and gloves.
• Wear wraparound sunglasses or goggles with 100% UV protection.
• Seek shade between 10 a.m. and 4 p.m. when the sun’s UV rays are strongest.

She advises you get to know your skin and check it monthly using the ABCDEs of melanoma guide. Visit a dermatologist yearly if you are at risk of skin cancer.

“Enjoy the sun and being outdoors, but be smart,” she says. “A few simple steps can help protect you from skin cancer.” 

Request an appointment at MD Anderson's Lyda Hill Cancer Prevention Center online or call 877-632-6789.