Reference Lab
JAN 19, 2021
Upd: APR 28, 2023
If you religiously apply sunscreen at the height of summer but are somewhat less diligent in the winter months, youโre not alone. A study published in The Archives of Dermatology found that many people are less likely to use sun protection because they presume that cold temperatures and clouds block harmful UV radiation.1 But did you know that thereโs a type of UV radiation thatโs actually equally strong all year long? Not only that, but the UV rays that cause skin cancer are still a very present danger to your skin in the winter months.
Letโs take a look at the compelling reasons why you should remember to wear your SPF even in cold and cloudy weather.01ย Why does UV exposure matter?
Both types of UV radiation cause DNA damage and together are responsible for an estimated 90% of visible skin aging.2 This damage is largely cumulative, which means that even small doses of radiation can have a big impact on your skin over time. Thatโs why dermatologists recommend wearing sunscreen every day, even if you arenโt going to be spending enough time in the sun to get a sunburn.
02ย How does sunscreen work?
Sometimes called physical or natural sunscreens, inorganic sun protectants like zinc oxide and titanium dioxide act like a physical shield on the surface of the skin. By reflecting UV radiation away from the skin, these ingredients protect you from the DNA-damaging impacts of UV rays.
Organic sun protectants, on the other hand, actually convert UV radiation into heat before it can damage the skin. Often called chemical sunscreens, these include ingredients like avobenzone and oxybenzone.
Both types of sun protectants are considered safe and can effectively block both UVA and UVB radiation. However, some ingredients work better to block UVA than others, so be sure to look for a broad-spectrum sunscreen that specifically block both types of rays.
03ย Why do we need sunscreen in winter?
UVB radiation, on the other hand, does vary in intensity throughout the year. But because UVB rays cause the majority of skin cancer, itโs important to take any possible exposure seriously. While these rays are less strong during the winter months and even weaker if you live on a very northern or very southern latitude, they can still cause sunburns and sun damage year-round in most regions, especially if thereโs snow on the ground.3
Snow can reflect up to 80% of UV rays. That means that youโre actually getting a double dose of exposure: once when the rays hit your skin directly and again when they reflect off of the snow onto your skin.4 In comparison, sea foam reflects about 25% of UV, and dry beach sand reflects about 15%.5 That means that in the winter season, you might actually be safer from UV rays on the beach than you are on the ski slopes.
In fact, if youโre spending your winter on the slopes, you might also have the high altitude to thank for increased UV exposure. At higher altitudes, the layer of atmosphere between you and the sun is thinner. This means that UV rays have less distance to travel and are stronger when they reach your skin than they are when youโre at sea level.6 This reinforces that wearing sunscreen in winter is still necessary to prevent effects of sun damage regardless of the season.
04ย Do you need sunscreen indoors?
05ย How to keep your skin protected
Key Takeaways
- There are two main forms of UV radiation that affect your skin: UVA and UVB radiation.
- UVA radiation is tied to skin aging and remains constant throughout the year, even in winter months.
- UVB radiation is tied to sunburn and skin cancer. Although it varies in intensity throughout the year, it is still a real danger to your skin in winter months.
- Snow and high altitudes can magnify the effects of UV radiation, making your skin more vulnerable during common winter activities like skiing and snowboarding.
- Incorporate SPF into your skin care routine all year round to keep your skin safe from the aging and cancer-causing impacts of UV exposure.
Sources:
- https://pubmed.ncbi.nlm.nih.gov/21079060/
- https://www.epa.gov/sunsafety/health-effects-uv-radiation
- https://www.epa.gov/sites/default/files/documents/uvradiation.pdf
- https://www.skincancer.org/press/the-skin-cancer-foundation-shares-winter-sun-protection-tips/
- https://apps.who.int/iris/handle/10665/42459
- https://www.skincancer.org/press/the-skin-cancer-foundation-shares-winter-sun-protection-tips/