Winter has a way of tricking us. Shorter days. Colder air. Less sweating. No beach trips. You step outside and the sun feels weak — almost harmless. But here’s the truth dermatologists wish everyone knew:

The winter sun can be deceptively damaging, especially when it comes to UVA exposure and long-term skin aging.

Let’s break down why winter sunlight shouldn’t be ignored, even when there’s frost on the ground and you haven’t seen the beach in months.

🌥️ 1. UVB Drops… But UVA Barely Changes

UVB (the “burning” rays) decrease significantly during winter — which is why sunburns feel less common.
But UVA? It stays nearly constant year-round (WHO, 2020).

UVA rays:

• Penetrate deeper into the skin
• Break down collagen
• Trigger pigmentation
• Speed up visible aging
• Pass through clouds, glass, fog, and rain
  

This is why dermatologists emphasize: just because you’re not burning doesn’t mean you’re not aging.

❄️ 2. The Ozone Layer May Be Thinner in Winter

Here’s something most people don’t know: winter ozone levels fluctuate in a way that can allow slightly more UVA to reach the ground (Bernhard et al., 2020).

The ozone layer mainly blocks UVB, but seasonal changes can shift the balance of wavelengths that make it through — leading to higher UVA percentages during colder months.

So even though total UV is lower, the type of UV that reaches your skin is more heavily weighted toward aging rays.

🏔️ 3. Reflection From Snow Increases UV Exposure

If you live anywhere with snow — or travel to snowy climates — UV exposure doesn’t just come from above. Snow can reflect up to 80% of UV radiation right back toward your face (Diffey, 2010).

That means:

• UV from above + below
• Higher risk of under-eye and chin exposure
• More intense damage at high altitudes
  

This makes winter sun potentially harsher than summer sun in certain environments.

🌡️ 4. Cold Temperatures Make You Think You’re Safe

In summer, heat warns you. You feel the sun.
In winter, cold air numbs your perception of UV exposure.

You won’t feel:

• Skin warming
• Skin tightening
• Early burn signals
  

But UVA is still hitting your skin the entire time.

🌬️ 5. Winter-Dry Skin Is More Susceptible to UV

Barrier function weakens in cold, dry conditions — making your skin more vulnerable to UV-induced irritation and pigmentation (Rawlings & Harding, 2004).

Meaning: the combination of dryness + UVA accelerates visible aging faster in winter than most people realize.

❄️ So… Is Winter Sun More Dangerous?

Not in terms of burning — but in terms of aging, hyperpigmentation, and collagen breakdown?

Yes. Winter sun can be more damaging because UVA makes up a higher proportion of UV exposure, your skin barrier is weaker, and reflective surfaces increase intensity.

Daily SPF is still essential — even when your breath feels colder than your iced coffee.

✨ Product Spotlight: SKINNY DIP (SPF 50)

The perfect winter SPF for everyday use — thin, mineral-based, and made for cold-weather wear.

Why Skinny Dip belongs in your winter routine:

• 100% mineral zinc oxide (the best UVA defense)
• Weightless, no white cast finish — great under makeup or bare skin
• Squalane replenishes moisture in dry winter air
• Niacinamide supports an even tone and calm complexion
• Hyaluronic Acid hydrates without heaviness
• Fragrance-free + gentle for sensitive, winter-stressed skin
• 80-minute water resistance (snowball fights included)
  

Winter sun is sneaky — Skinny Dip is your daily shield.

References (APA):

Bernhard, G., et al. (2020). Seasonal variability in erythemal irradiance. Journal of Geophysical Research: Atmospheres.
Diffey, B. (2010). Solar ultraviolet radiation effects on biological systems. Physics in Medicine & Biology, 55(S1).
Rawlings, A. V., & Harding, C. R. (2004). Moisturization and skin barrier function. Dermatologic Therapy, 17(S1).
World Health Organization. (2020). Radiation: Ultraviolet. https://www.who.int/news-room/q-a-detail/radiation-ultraviolet