Short answer: on a ski day your lips get hit twice. The sun is stronger up high, and snow throws a lot of that UV straight back up at your face. Lips have very little melanin and thin skin, so they burn fast and heal slowly.
Why is the sun stronger on the mountain?
There's less air above you to filter UV. According to the World Health Organization, UV levels rise by about 10% for every 1,000 m you climb. A resort at 2,000 m can get around 20% more UV than the beach, even when it feels freezing.
Why does snow make it worse?
Fresh snow reflects up to 80% of UV radiation, so you get it from above and below. That's why ski-day sunburn often shows up under the chin, on the nose and on the lower lip, places that normally sit in shade.
Why lips in particular?
- Lips have very little melanin, the pigment that gives skin some natural defense.
- The skin on your lips is thinner than the skin on your face.
- Wind and cold dry them out, and licking your lips makes it worse.
5 things that actually help
- Use a lip balm with SPF, not a plain balm. A normal balm softens lips but doesn't block UV. In the EU, SPF 30 counts as high protection.
- Check for UVA protection. SPF only measures UVB. Look for UVA tested, or the UVA logo in a circle on EU products.
- Put it on before the first lift. Not once your lips already sting.
- Reapply often. At least every 2 hours, and after eating, drinking or wiping your face with a glove.
- Keep it where you can reach it. A stick in a chest pocket gets used. One at the bottom of your backpack doesn't.
Signs your lips are already burned
Swelling, a tight burning feeling, redness along the edge of the lips and small blisters a day later. Get out of the sun, keep them moisturised with a plain balm and see a doctor if it's severe or doesn't settle.
Quick questions
Can I skip it when it's cloudy?
No. Much of the UV still gets through light cloud, and snow keeps reflecting it.
Is SPF 15 enough for skiing?
For a full day on snow, SPF 30 or higher is the safer choice.
Does face sunscreen work on lips?
It can, but most people stop using it because of the taste. The best lip SPF is the one you keep reapplying.
What we use
We made the WanderfulSouls SPF 30 Lip Shield for exactly this: SPF 30 tested on people, UVA tested, no white cast, and small enough to live in your ski jacket. Get your stick.