7 Cases When You Think You Don't Need Sunscreen—but You Do

Dermatologists weigh in on the risk of going without sun protection when it may seem unnecessary

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Senior adult with toddler on a beach during a cloudy day. Photo: Andrew Zaeh/Getty Images

If it’s a hot, sunny day and you’re going to be outdoors for hours, you may already know you should slather on sunscreen before leaving the house. But what about when it’s not so sunny, you don’t plan to be out long, or maybe you’re not outside at all—just sitting near a sunny window? Even people who are diligent about sun protection may let their guard down on occasions when sunscreen doesn’t seem as important.

“It’s a popular misconception that you don’t need sunscreen in certain scenarios, such as a cloudy day or when you’re just running a quick errand,” says Valerie Harvey, MD, director of the Hampton University Skin of Color Research Institute and president-elect of the Skin of Color Society. “But the fact is that any time in the sun is potentially risky and requires smart sun behavior.”

While it’s true that there’s no such thing as a “safe” amount of time to be in the sun unprotected, some situations are riskier than others. We asked dermatologists to help determine how damaging seven scenarios might be to your skin if you haven’t applied sunscreen.

It's Cloudy

Risk level: High

“Contrary to popular belief, you are at risk for sun damage even if you can’t see the sun,” says Joshua Zeichner, MD, an associate professor of dermatology at Mount Sinai Hospital in New York.

More on Sun Protection

About 80 percent of ultraviolet rays penetrate right through the clouds to reach your skin. Spending time outside without sunscreen on an overcast day is very risky, experts agree. If you’re curious about how strong UV rays are, even on a cloudy day, check the UV Index, which can be found on most weather apps. It’s a tool that ranks the sun’s intensity on a scale of 1 to 11+.  Dermatologists say that when the UV Index is 3 or higher, it’s especially important to protect your skin.

You Won't Be Outside Long

Risk level: Low

Forgetting your sunscreen for the occasional short outing—commuting to work, running some errands, eating a quick lunch on the patio—isn’t the end of the world. “But if you do that every day, the sun damage will add up,” says Mona Gohara, MD, an associate clinical professor of dermatology at the Yale School of Medicine. “Even a 5-minute walk every day at lunch means a lot of cumulative sun exposure over the course of a year.”

You've Got a Base Tan

Risk level: High

“Your skin color at the time of unprotected sun exposure can protect you to some extent, because the more melanin [pigment] you have in your skin, the more protection you have,” says Maritza Perez, MD, a professor of dermatology at the University of Connecticut School of Medicine. But a tan is actually a sign that you’ve already damaged your skin, so you should be more careful about shielding it. And even people with naturally dark skin need to protect it from the sun.

You're Driving

Risk level: High

Glass does block most UVB rays, so you won’t get sunburned through a window. But UVA rays—the ones that cause skin aging and contribute to skin cancer—can penetrate most window glass unless it’s been specially treated with UV-blocking tint. That includes the windows in your home or office as well as your car, and the damage is cumulative. If you drive often—and for long distances—you should apply sunscreen. Gohara notes that skin cancer on the left side of the face and body is much more common as a result of people logging a lot of time behind the wheel.

You're Wearing Makeup With SPF

Risk level: Medium

Using a foundation or powder that contains sunscreen may be better than nothing, but not by much. The biggest problem with SPF makeup is that it’s nearly impossible to use enough—or reapply frequently enough—to achieve adequate protection. You need to use a full teaspoon of sunscreen to protect your face. “If you used that much foundation, your makeup would look caked on,” says Zeichner. “Think of makeup with SPF like icing on the cake to give added protection over your base layer of sunscreen.”

You Put Sunscreen on Before You Went to the Beach and Didn’t Go Into the Water

Risk level: Low for the first 2 hours. Very High after 2 hours.

If you’ve done a thorough job of applying a broad-spectrum sunscreen with an SPF of 30 or higher, your skin will be well protected for your first couple of hours poolside or at the beach. (Experts still recommend you sit under an umbrella and cover up with clothing and a wide-brimmed hat for extra protection.) But a single application of sunscreen—no matter how much you slather on or how high the SPF—doesn’t last all day. “You need to do a full reapplication every 2 hours—even if you’re not getting wet,” Zeichner says. If you skip that, you’re very likely to go home with a sunburn. And if you do go in the water, be sure to reapply sunscreen even if you’re in the first 2-hour window.

It’s Late Afternoon

Risk level: Low

The sun’s rays are strongest between 10 a.m. and 4 p.m. The intensity of the burning UVB rays diminishes a little bit every hour after that. The closer it is to sunset, the weaker the sun’s rays will be. But as long as there’s daylight, UVA rays maintain their intensity. Where you live will also affect just how strong the sun is, even late in the day. Being closer to the equator or at a high altitude means you’ll experience more intense sunlight at all times of day.

Sally Wadyka

Sally Wadyka is a freelance writer who contributes to Consumer Reports, Real Simple, Martha Stewart Living, Yoga Journal, and the Food Network on topics such as health, nutrition, and wellness.