The driest place on earth is the dry valley of the Antarctic continent. The valley here has not rained for two thousand years. Except for one valley, the lakes in this valley are temporarily filled with inland river water in summer, and the dry valley does not contain moisture (water, ice or snow). This is why the dry valley has a wind speed of 320 kilometers per hour. The reason is that the wind evaporates all the water vapor.
These dry valleys are peculiar: apart from the barren gravel scattered on the ground, they are the only land in Antarctica that is not covered by ice and snow. Dry valleys are located across the mountains of Antarctica. They are in mountain regions where evaporation (or sublimation of the Atacama Desert) is more than snowfall, so all the ice is gone, leaving only dry and barren land.
The other driest place on earth is the Atacama Desert in Chile, where there has been no rainfall for centuries. It is hard to imagine that a drought lasted for 400 years, but it did happen in parts of Chile’s Atacama Desert. These areas rained for the first time in 1971 since the end of the 16th century. It never rains in Arica at the northern end of the Atacama Desert. It has become a well-known holiday destination, relying on pipeline water from the Andes to supply water.
Extending about 960 kilometers south from the border of Chile and Peru, the terrain is generally much higher than sea level, with an average of 610 meters. It consists of a series of saline-alkali basins with almost no plants.
Why is the Atacama Desert so dry? Part of the reason is that the cold Antarctic current produces a lot of fog and clouds, but there is no rainfall; another part of the reason is that the Andes Mountains to the east are like a barrier, blocking the humid air from the Amazon basin that may form rain clouds.