Should You Wear Sunscreen on Cloudy Days? (Yes!)

Should you wear sunscreen? “Only if it’s sunny out!” That’s the way a lot of us think. If it’s cloudy, rainy, or cold outside, it’s easy to assume you’re safe.

But anyone who’s gotten a sunburn while skiing knows that’s not true. In this post, I’ll break down the myths about weather and explain why it is so important to wear sunscreen everyday, even on cloudy days.

Why Should You Wear Sunscreen on Cloudy Days?

Let me drop some science on ya. Clouds filter out sunlight but not UV rays, the bad ones that cause aging and cancer. The Skin Cancer Foundation says that clouds block as little as 20% of UV rays — so on a cloudy day you’re still getting up to 80% of the sun’s harsh effects.

Some say you’re actually at more risk on cloudy days, since UV rays can bounce off of clouds. According to American Scientist, “Reflection off the sides of cumulus clouds is one mechanism by which UV radiation can become focused.” The science may be hard to grasp, because it depends on the thickness of the clouds and how much of the sky they cover — factors that can change within minutes. But the bottom line is, yes, you should still wear sunscreen on cloudy days.

Should You Wear Sunscreen on Cold or Rainy Days?

Yes, always yes. Don’t think that rain or cold weather automatically means you can’t get burned. Sometimes you get an odd day that’s sunny and rainy at the same time. Basically, you’re better off just being in the habit of wearing sunscreen every day!

It is also important to note that UV rays are independent of temperature — so you can get just as much sun damage on a cold, sunny day than you can a hot summer one. Ireland’s Public Health Agency says, “Cool bright days even with light cloud can have damaging levels of UV radiation.”

When You’re Especially at Risk

Some conditions make you extra-vulnerable to ultraviolet rays: snow and ice, lakes and other bodies of water, white sandy beaches, and even concrete. All of these surfaces can act as mirrors, bouncing the sun back at you and exposing you to more UV rays. According to CNN, snow reflects up to 80% of UV rays, and sand reflects almost 20%. Sea foam reflects about 25%.

So if you’re going surfing, fishing, or just enjoying the great outdoors on a slightly cloudy day, definitely wear sunscreen. Other factors that can increase your UV risk are being closer to the equator, being at a high elevation, and being outside when the sun’s rays are the strongest (10 a.m. to 4 p.m.). Take extra precautions then, like staying inside or wearing sun-protective clothing.

Should You Wear Sunscreen in the Shade?

This is a fantastic question. The U.S. Department of Energy actually answered this in their “Ask a Scientist” feature, so I’m going to let Dr. Richard E. Barrans, Jr. take this one:

“[I]t is also possible to get a sunburn while sitting in the shade. Ultraviolet rays scatter more strongly in the atmosphere than visible light, so they can literally bounce off the air and then to you even if you are in the shade. If you can see blue sky, you are getting scattered UV.”
With sun protection, better safe than sorry, right?

The UV Index

Another sunscreen indicator is the international UV index. It’s a daily rating from 1 to 20 of how much UV radiation will reach your area, and how much your risk is. At about 3, you should definitely wear sunscreen. Google your city name and “UV index” to see what yours is. For instance, today in Portland, our UV index is 1 (low). But because we’re having patchy clouds with some sun shining through, it’s definitely smart to wear sun protection.

Bottom Line

Yes, sunscreen is important — but it’s not your only tool to fight cancer-causing UV rays. Sun-protective clothing is a great choice. As NYU dermatologist Jennifer Stein told WebMD, “Clothing and a hat are even better than sunscreen. The more covered up you are, the less sunscreen you need.” Try a sun-protective hat or our infinity scarf — it has an ultraviolet protection factor (UPF) of 50+, which means it blocks over 98% of UV rays. You can protect your skin and stay stylish, too.

See you outside — I’ll be the one in the cute straw fedora! 

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