Climate of Chile

The climate of Chile comprises a wide range of weather conditions across a large geographic scale, extending across 38 degrees in latitude, making generalizations difficult.

On a synoptic scale, the most important factors that control the climate in Chile are the Pacific Anticyclone, the southern circumpolar low pressure area, the cold Humboldt current, the Chilean Coast Range and the Andes Mountains.

In the extreme northeast and southeast the border of Chile extends beyond the Andes into the Altiplano and the Patagonian plains, giving these regions climate patterns similar to those seen in Bolivia and Argentina respectively.

[4] The Atacama Desert is the driest place on Earth, and is virtually sterile because it is blocked from moisture on both sides by the Andes mountains and by the Chilean Coast Range.

Some locations in the Atacama do receive a marine fog known locally as the Camanchaca (garúa in Peru), providing sufficient moisture for hypolithic algae, lichens and even some cacti.

As the climate map shows, where elevation is high enough to preclude any month with an average temperature of 10°C, precipitation is low enough to allow a transition between a cold desert (Köppen classification BWk) and tundra (ET).

The numerous rivers greatly increase their flow as a result of the winter rains and the spring melting of the Andean snows, and they contract considerably in the summer.

This more or less drastic transition is caused by the split of the westerlies at these latitudes (~37° S) into one branch going to the southeast and another to the northeast, to this it is necessary to add the north-south lowering of the Chilean Coast Range which reduced the rain shadow effect.