UV Safety Starts Now: June's Daily UV Reality
Peak-season UV demands peak-season habits.
At a ski resort at 10,000 feet, UV can be ~40-50% stronger than at sea level.
Up to 80% of UV penetrates clouds, so overcast days are not protection.
Frequently asked questions
Is sunscreen necessary on cloudy days?
Yes. Up to 80% of UV rays pass through clouds, and UVA — the deeper-penetrating, aging wavelength — stays fairly constant regardless of cloud cover. A cool, overcast day can still deliver enough UV to damage skin, so daily broad-spectrum sunscreen is recommended.
Does UV get stronger at higher altitude?
Yes. UV intensity increases roughly 4–5% for every 1,000 feet (about 300 m) of elevation, because there's less atmosphere to filter it. At a mountain resort UV exposure can be substantially higher than at sea level — a key reason sunburn is common while hiking or skiing.
Do I need sunscreen while skiing?
Definitely. On the slopes snow reflects up to 80% of UV and altitude raises intensity about 4–5% per 1,000 feet, so exposure is intense even in the cold. Use broad-spectrum SPF 30+ on the face, ears and neck, an SPF lip balm, and UV-blocking goggles.
r/SkincareScience: 'Does snow really reflect that much UV?'
Sources & citations
- WHO, 'Global Solar UV Index: A Practical Guide' (reflection & altitude)
- epa.gov ↗