Smarter: Is Sunscreen Necessary on Cloudy Days?

Do I have to put sunscreen on if it’s an overcast or rainy day?
Yes, because even on overcast days, up to 80 percent of UV rays can still penetrate light cloud cover and reach your skin, according to the World Health Organization.

Can I skip sunscreen if I’m going out after 5 p.m.?
After 5 p.m., you’re less likely to get burned without sunscreen because the UVB rays, which cause sunburn, are less intense. However, you should still wear sunscreen because as long as there is daylight, there are UVA rays, and those contribute to aging and skin cancer, says Trisha Calvo, a CR deputy editor who has written dozens of articles on sunscreens in her eight years at CR.

What about early mornings?
Yup. Then, too. The sun is strongest between the hours of 10 a.m. and 4 p.m., but just like late-afternoon sunlight, morning rays can damage your skin. Especially in the summer, it’s good to wear sunscreen even if it’s early in the morning if you’re going outside, says Laura Ferris, MD, PhD, professor of dermatology at the University of Pittsburgh.

Okay, what about at home? I don’t have to wear sunscreen if I don’t go out, right?
If you are near a window or skylight that doesn’t have UV protective film for a long period of time at home, it’s recommended that you still put sunscreen on exposed skin because UVA rays can pass through glass, says Susan Booth, who oversees CR’s sunscreen testing and has evaluated hundreds of sunscreens.

Well, what about if I’m in a car?
Yup, you still need it. While windshields made from laminated glass block almost all UVB rays and 98 percent of UVA rays, 79 percent of skin-damaging UVA rays can pass through the side and rear window glass. 

In case you need more convincing, this picture of the sun damage on the left side of a trucker’s face after 28 years of being on the road speaks for itself, really.

If I’m covered up, do I need to put sunscreen under my clothes?
Focus on sunscreen on exposed skin, says Dathan Hamann, MD, medical director at the Contact Dermatitis Institute, a dermatology clinic in Phoenix. And it’s worth noting that sunscreen is just one of several methods to stay safe in the sun. Sun-protective clothing with a UPF (ultraviolet protection factor) rating can also help protect you from the harmful rays of the sun. So does seeking shade and wearing wide-brimmed hats and sunglasses. 

“The best sun protection is achieved when using multiple methods on a routine basis,” says Ivy Lee, MD, board-certified dermatologist and fellow of the American Academy of Dermatology.

What if I’m just going out for a few minutes?
Daily sunscreen is helpful in protecting your skin even just for brief errands. Many people actually do not get most of their sun exposure and damage from laying out under the sun. Instead, it is the short moments of running in and out of doors that we accumulate sun damage, Ivy says.

If you find it cumbersome to apply sunscreen every time you’re going to pop out the door for a few minutes, an easy way to protect your skin is to incorporate sunscreen into your morning regimen. It’s like brushing your teeth or taking vitamins—you can make it a daily habit, not something dependent on the weather or your daily activities, Dathan says.

Have more questions about sunscreen? You can read our answers to common questions about sunscreen, including whether sunscreen expires and whether you need sunscreen if you have darker skin. (Spoilers: Yes and yes.) 

Or hit me up with your most pressing question, and I’ll shed some non-skin-damaging light on it.