Why Are the World's Deserts Located at 30 Degrees Latitude?

Deserts on Earth exist at 30 degrees latitude because of warm air, calm winds and virtually constant areas of high pressure forming in the atmosphere above. These deserts experience dry and hot conditions year-round and see plenty of sunlight, little wind and very little precipitation. This area of desert lands forms in the areas of latitude 30 degrees north to 30 degrees south of the Equator.