Do I Really Need SPF Indoors (or in Winter)?
TL;DR
Yes! UVA rays penetrate windows, clouds, and even bounce off snow. That means your skin is still exposed indoors and during colder months. Daily sunscreen is the simplest, smartest way to protect your skin year-round.
Why People Skip Daily SPF (and Why It’s a Mistake)
Sunscreen has always been marketed as a “summer product.” It makes sense: hot weather, beach days, and vacation packing lists are when most people remember SPF. But the reality is:
- UV rays don’t stop at glass
- Cold weather doesn’t block sun damage
- Cloudy skies don’t filter enough radiation
This gap between perception and reality is why dermatologists emphasize year-round, daily sunscreen use and not just when it’s hot and sunny.
Do Windows Block UV Rays? Why Indoor Sunscreen Still Matters
Not really. Here's why:
- Windows block UVB (the burn rays) but not UVA (the aging + damage rays). That’s why you can still see skin damage while driving or sitting near a window
- Screens add another layer. While your laptop or phone won’t burn you, some research suggests visible light—especially blue light—may contribute to pigmentation over time. A daily mineral SPF helps keep skin even-toned and protected
Sunscreen in Winter: Do Cold Temps Mean Safe Skin?
UV exposure doesn’t disappear in cold weather. In fact, some risks increase:
- Snow reflects up to 80% of UV rays, doubling your exposure when skiing, hiking, or even just walking outside
- Clouds let up to 80% of UV radiation through. Gray skies aren’t a free pass
- Skin is often drier and more fragile in winter, which makes protection even more important
The Benefits of Daily SPF: Year-Round Skin Protection
Consistent daily SPF helps prevent:
- Premature aging (fine lines, wrinkles, hyperpigmentation)
- Long-term skin damage and barrier breakdown
- Increased risk of skin cancer
UV damage is cumulative, so even if you’re mostly indoors, those few hours near a window or quick errands outside add up.
How to Build the Habit
- Keep your sunscreen next to your toothbrush so it becomes part of your morning routine
- Choose mineral-based sunscreen with zinc oxide or titanium dioxide for instant, broad-spectrum protection
- Pick lightweight, skincare-like formulas that you’ll actually want to wear every day
Daily sunscreen doesn’t need to be complicated; it just needs to be consistent.
Bottom Line
Yes, you need sunscreen indoors and in winter. If you can see daylight, your skin can see UV. The best sunscreen is the one you’ll wear every single day, no matter the season.