How to layer for Peru's extreme climate changes

Dress in three distinct layers: a moisture-wicking base, a fleece or down mid-layer for insulation, and a waterproof, windproof outer shell. You will need to strip down to a t-shirt in the coastal sun and bundle up in four layers once the sun sets in the high Andes.

  1. Manage the coastal heat. In Lima and along the coast, wear lightweight, breathable cotton or linen fabrics. A light windbreaker is sufficient for the misty, cool mornings common in Lima.
  2. Layer for the Andean altitude. At high altitudes like Cusco or Lake Titicaca, temperatures swing 20°C (36°F) between day and night. Always wear a thermal base layer, a wool sweater or heavy fleece, and a packable down jacket.
  3. Prepare for the cloud forest. When visiting Machu Picchu or the Amazon, humidity is high and rain is frequent. Use synthetic, quick-dry pants and shirts. Avoid jeans, as they take days to dry in the damp mountain air.
  4. Protect against extreme UV. The sun at 3,000+ meters is punishing. Always wear a wide-brimmed hat, polarized sunglasses, and SPF 50+ sunscreen, even if it feels cold outside.
Do I really need heavy winter gear for Cusco?
Yes. Even if the sun is out, once it drops behind the mountains, temperatures plummet to near freezing. You will want a down jacket every single night.
Can I buy clothes in Peru if I forget something?
Yes. Cusco and Lima have excellent outdoor gear shops. Look for local alpaca wool garments; they are better at regulating temperature than mass-produced synthetics.
Is it okay to wear shorts in the mountains?
Generally, no. Apart from the cold, the high-altitude sun burns skin in minutes and insects in the cloud forest can be aggressive. Long, lightweight trousers are safer and more culturally appropriate.