Behavior
Seasonal Sun Exposure: Why Winter UV Still Matters
UV doesn't take winters off. How seasonal changes — snow reflection, altitude, sunny vacations — still expose your skin year-round.
Most people associate sunburn with summer. But dermatologists see plenty of winter sun damage — especially from skiing, hiking at altitude, and tropical vacations.
Snow reflects up to 80% of UV
Fresh snow reflects much more UV than grass, sand, or water. At altitude — every 1,000 meters of elevation increases UV by roughly 10% — that combination can produce surprisingly high UV indices on a cold, sunny February day.
The vacation spike
Two weeks in a sunny destination after months of low UV is a classic burn scenario. Your skin hasn't built any tolerance, the UV is unfamiliar, and outdoor time is concentrated. Treat winter beach trips like high-summer days from day one: SPF, hat, shade.
Window and incidental UV
UVA passes through standard glass — meaning you accumulate a small daily dose driving or sitting by a window. Daily facial SPF makes more sense than people realize, even if you ‘never go outside.’
Key takeaways
- Winter UV at altitude can match summer levels.
- Snow reflection roughly doubles your effective dose.
- Daily facial sunscreen helps with incidental UVA exposure indoors.