There is a saying in tropical mountain chains that goes: "there are no seasons throughout the year, but rather days that feature all four". In the Peruvian Andes, in the morning there is sunshine but the air is cool, like in spring; after midday the sun heats up, and one often has to take to the shade, as during the as during the summer ; in the afternoon , the clouds

that have gathered all morning long begin to cover the sun, and it feels like autumn; when the skies are completely overcast, it becomes so cold that it feels like winter.

Snow conditions
Glaciers are also receding in the Andes, where the snowline loses two meters every year. This sparks continuous changes in the aspect of the mountains, access routes and how to tackle them. Large chunks of compact snow called seracs constantly break away from the mountains. Rain in the valley generally turns to snow above 4,500 meters. Snow generally sticks well to steep Andean slopes, and often forms cornices on cliffs on the windless side of the summit.

Occasionally one comes across cornices on both sides of a cliff. Another characteristic of the region is the formation of layered walls of snow.Because the mountains are located in the Southern Hemisphere, the consequences of the directions the various mountain slopes face change compared to the Northern Hemisphere.