The best time for mountain climbing in Peru is the South American winter; April to September, with the driest months being June and July. Early in the season there is more accumulated snow left over from the rainy season, by August the glaciers are usually quite dry and more crevasses will have opened up. These conditions can affect route conditions over the season, for example: the normal routes on some mountains like Huascaran or Chopicalqui can be impassable late in the season due to a large crevasse that has opened up. In my experience the best time to climb your project peak is July 15th to August 15th.

It is very important to acclimatize properly. If you are just arriving to Cusco, I recommend at least 3 full nights in Cusco (3,300mts/10,824ft) before sleeping higher than 4,000mts (13,120ft). It is recommendable to climb a peak of 5,500 meters, before a 6,000 meter peak if you have the time. If you are already well acclimated, it is possible to go directly to climb an easier 6,000mts peak like Ausangate, Chumpe or Yayamari. These guidelines should be regarded as the minimums. Often people have a tight schedule and want to do as much as possible with their time, but acclimatization is important for you to be able to accomplish your goals.

Temperatures in the mountains during the day can vary greatly depending on weather conditions. Above 4,000 meters in altitude, If the sun is out and there is no wind, it can be up to 65F (18C) during the day. At night during clear weather it can get down to 23F (-5C). Above 5,000 meters in altitude, for example at the moraine camp (5,500m) of Ausangate it can get down to 14F (-10C) during the night. Above 6,000m it can get down to -4F (-20C) and even colder when you factor in the windchill.

There is much more solar radiation at altitude in Peru, Ecuador and Bolivia than other places because they are tropical ranges. It is very important to protect your skin and eyes from these conditions so that you don’t go snow blind after climbing. Anyone who climbs in the Andes needs good sunglasses and we suggest to have a brimmed hat and plenty of sunscreen, even for your lips.

It is important to have your layer system dialed in so you can climb fast while not getting overheated. Everyone feels the cold and conditions differently but I will give you the example of my own system. Lower body - 3 layer system: - Base layer: Thermal tights - Mid layer: Alpaca wool pants or down pants - Outer Shell: Waterproof pants (goretex or similar) Upper body - 4 layer system: - Base Layer: Under armour cold gear long sleeve shirt - Light Mid layer: Synthetic down hoodie - Heavy Mid Layer: 700+ fill Down jacket - Outer Shell: Waterproof jacket with hood that can go over helmet (goretex or similar)

The most important pieces of clothing/gear for mountaineering are where your body makes contact with the mountain: gloves and boots. I would recommend single boots like the Scarpa Mont Blanc or La Sportiva Nepal Evo or similar boots for peaks that are 5,000 meters up to a peak like Tocllaraju (6,034m) that just goes over 6,000m. For anything higher like Ausangate (6,384m) or Huascaran (6,770m) double boots are best for most people but not absolutely necessary. I personally use the Scarpa Phantom 6,000, because Scarpa boots have a wider toe box for my wide feet than La Sportiva boots. But there are good La Sportiva models also like the Spantik or the G2 SM. As with all mountaineering boots, buy them a size larger so you have room for an extra sock or wiggle room to keep the circulation going.