Which desert is widely considered the driest non-polar desert on Earth?

Which desert is widely considered the driest non-polar desert on Earth? The Atacama Desert.

The Atacama stretches along the Pacific coast of northern Chile, mainly between the coastal mountains and the Andes. It is widely regarded as the driest non-polar desert on Earth and is often described as the driest place outside the polar regions.

Its extreme aridity has several causes. The cold north-flowing Humboldt Current stabilizes the atmosphere, while the Pacific subtropical anticyclone suppresses rainfall. The Andes block moist air from the Amazon Basin, and the Coastal Range helps create another rain shadow from the Pacific. Together, these features leave some parts exceptionally dry.

Average rainfall is roughly 15 millimeters per year, while certain locations receive only trace amounts. Some weather stations have recorded no rain, and the central desert has experienced multi-year dry periods. The landscape’s barren, Mars-like conditions have made it useful for testing instruments and procedures for future Mars missions. The Atacama is not the driest environment overall: Antarctica’s McMurdo Dry Valleys are drier in specific places, but they are polar.