The Atacama Desert is the world’s driest non-polar desert by average rainfall and lies along Peru’s and Chile’s Pacific coast.
The Atacama occupies a narrow coastal region west of the Andes, mainly in northern Chile and extending into southern Peru. Its exceptional dryness results from several interacting factors: the cold Humboldt Current limits evaporation and cloud development, the Andes block moist air from the east, and descending air associated with subtropical high pressure suppresses rainfall.
Some parts of the desert receive almost no measurable rain for years, although rare storms can produce spectacular blooms in areas known as the flowering desert. Coastal fog called camanchaca can provide moisture for specialized plants and animals even when rainfall is absent.
The Atacama is often described as the driest non-polar desert, not the driest place of every kind on Earth. Antarctica is a polar desert and is much larger. The Atacama is also important for copper mining and for astronomical observatories because its clear, dry skies reduce atmospheric interference.