Here are a few important details to consider before deciding to climb the highest mountain outside the Himalayas:

Season

The best time to climb Aconcagua is during the austral summer, from December to March, because of the weather conditions. January is particularly favourable.

Although the effects of altitude are significant, the use of supplementary oxygen is not necessary.

In all, the mountain offers a choice of thirty-three routes.

The different routes

The Normal route: Technically speaking, the approach from the north, the Normal route, is relatively easy. There is virtually no snow in summer, and a well-marked trail leads up to the Canaleta at 6,700 meters. The record for the fastest ascent of the Normal Route from base camp is 5 hours 45 minutes, set in 1991.

The Polish side: The second most popular route is the Polish Glacier Traverse Route, which follows the Valle de las Vacas,  crosses the Los Polacos glacier and then joins the Normal Route for the final ascent to the summit. The base camp is located at Plaza Argentina, and it is possible to join the Normal Route by descending to Plaza de Mulas. The first ascent of the Polish route was made on March 8, 1934 from the left side of the glacier.

South face: the numerous routes via the South and Southwest ridges are very difficult. This face features a 3,000-metre-high vertical wall conquered by a French expedition in 1954, hence the name French Route Inferior Horcones.

West face: The West face features three poorly-traced routes. The 1953 Marmillod-Grajales route follows the South-West face, with possible camps at 5,500 m, 5,700 m and 6,400 m, and has a 1979 variant.

The Mendocina 1988 route attacks the West Face in the center. The 1982 Mendocina route, opened by Carlos Sansoni and Sergio Buglio, is more direct along the Southwest ridge, but also more difficult.

The ascent via the “Falso de los Polacos

Our route, the north-facing Polonais slope, offers unrivalled high-mountain terrain: impressive glacier, grandiose panorama, endless ridge.

From the second day of the approach hike, the Polonais glacier can be seen at the bottom of the valley. For the rest of the way, the mountain grows at every bend in the path, finally presenting itself to us in all its splendour at the Plaza Argentina base camp at 4,200 metres.

This is where the work begins!

Level of difficulty

This trip requires excellent physical condition and psychological stamina to succeed. The ascent of Aconcagua on the Polish side, with the finale on the normal route (Falso), offers a fascinating challenge. This is complemented by a descent on the normal route to give us an experience of both sides of this giant of the Americas. It’s important to have as much previous experience as possible, but it’s not compulsory.

Weather

Aconcagua is located in the Cordillera Principal or Cordillera Frontera (Cordillera del Límite), in a semi-desert region that has earned it the nickname “The Arid Andes”. The scarcity of precipitation and the violence of winds blowing at up to 250 km/h explain the small amount of eternal snow that covers the summit.

Climatic changes are rapid and daily contrasts significant in summer, so much so that night-time temperatures can be largely negative at altitude. In winter, snow can fall below 4,000 meters. The seasonal melting of snow creates large, sharp ice formations up to thirty meters high, known as “penitents” on the glaciers.

In summer, the mountain receives most of its annual precipitation, brought in from the west by moisture-laden winds over the Pacific. These winds travel up the slopes of the mountain range, cooling and condensing. They form the famous lenticular clouds known as viento blanco or “white winds”, which sometimes cover the peaks and herald snow and strong winds at altitude. They can also generate violent thunderstorms, with the formation of pluma, long tapering clouds, in the valleys. But the Aconcagua summit is mostly spared these atmospheric conditions, and enjoys more sunshine than the valleys.
See a short video of the winds at Camp 1 below.