Once the weather cools off, sunscreen tends to migrate to the back of the cabinet. It feels logical: less heat, less sun, less to worry about. But UV isn't the same thing as warmth, and a few common beliefs about winter sun don't hold up well against what health agencies actually say.

Here are five winter UV myths, what the evidence says, and what UPF 50+ coverage in winter can realistically look like for a family with little kids.

Myth 1: "It's Cold, So There's No UV to Worry About"

What the evidence says: UV levels do change with the seasons. EPA's guide to the UV Index says UV peaks in spring and summer, declines in fall and is lowest in winter. Lower isn't zero, though. The CDC says protection from the sun is important all year, not just during the summer, and that the sun's rays can reach you on cloudy and cool days. EPA also advises limiting sun exposure during midday hours "even in winter and especially at higher altitudes."

What that means for you: temperature isn't a UV reading. Check the UV index in winter the same way you would in July. The CDC recommends protecting skin when the UV Index is 3 or higher.

Myth 2: "Clouds Block the Sun"

What the evidence says: Clouds reduce UV, but by much less than most people assume. The FDA notes that even on an overcast day, up to 80% of the sun's UV rays can get through the clouds. EPA gives typical transmission figures: scattered clouds let through about 89% of UV, broken clouds about 73%, and overcast skies about 31%.

What that means for you: a gray sky isn't a reason to skip the hat.

Myth 3: "Snow Doesn't Really Matter"

What the evidence says: Does snow reflect UV? Yes, a lot of it. EPA's UV Index guide says snow may reflect as much as 80% of UV, compared with about 15% for sand and 10% for water (a property called albedo). The same guide notes UV increases about 2% for every 1,000-foot increase in elevation. The World Health Organization also lists fresh snow among reflective surfaces that increase UV levels.

What that means for you: a snow day, or a ski trip in the mountains, can mean UV coming from above and bouncing up from below. Faces, ears and necks are easy to miss.

Myth 4: "Darker Skin Doesn't Need UPF 50+ coverage"

What the evidence says: The CDC is direct about this: "Anyone can get a sunburn no matter their race, ethnicity, or skin tone." People with lighter natural skin color are at higher risk, but the CDC also notes that sunburn at any age increases a person's risk of getting skin cancer.

What that means for you: the same basic habits (shade, clothing, hat, sunscreen on exposed skin) apply to every child, all year.

Myth 5: "Windows Block All UV"

This one is more nuanced, so it's worth getting right.

• At home: According to the Skin Cancer Foundation, window glass does a good job of filtering out most UVB rays, but UVA rays pass through windows.
• In the car: The Skin Cancer Foundation explains that front windshields are laminated glass treated to shield from some UVA, while side, back and sunroof windows are usually tempered glass, which doesn't block UVA as effectively. A 2016 study in JAMA Ophthalmology measured 29 cars from 15 manufacturers: windshields blocked an average of 96% of UVA, side windows an average of 71%, and only 4 of the 29 cars had side windows blocking more than 90%.

What that means for you: sitting by a window isn't the same as being outdoors, but glass isn't a complete UV shield either, especially side windows on long drives. Sleeves, window shades or UV window film are practical options the Skin Cancer Foundation discusses for UV through car windows.

A Simple Cold-Weather Sun Checklist

• ☐ Check the UV Index, not the thermometer. You can look up the forecast for your location through EPA's UV Index page.
• ☐ A hat and sunglasses for longer outings, especially on snow. EPA recommends a wide-brimmed hat and sunglasses when possible.
• ☐ Sunscreen on exposed skin. The American Academy of Dermatology recommends broad-spectrum, water-resistant SPF 30 or higher, reapplied at least every two hours, and reminds you not to miss ears, nose, lips, the back of the neck and the tops of hands.
• ☐ A long-sleeve layer. The CDC suggests long sleeves when possible. Kids often shed coats once they start running around, so the layer underneath is the one doing the work.

That last point is where everyday clothing helps. Our long-sleeve styles, like Puzzle Thinker, Sun Loading and Sweet As Can, are made from 100% GOTS-Certified Organic Cotton (see how we source it), and styles labeled UPF 50+ use fabric independently tested by TÜV SÜD. They layer under a jacket and still work as a regular tee once the jacket comes off. Browse them on our UPF 50+ collection.

The UPF rating applies only to the skin the fabric covers, so keep the hat and sunscreen for everything else. For more on why we design for daily wear, read Everyday UPF Clothing for Kids. If you'd like the basics of what UPF measures, see UPF 50+ Clothing for Kids, Explained or our What Is UPF 50+ page. To keep those layers working season after season, follow our care guide.

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