Where Are the World's Dry Deserts Located? The Subtropical Belt Explained

Dry deserts—those receiving less than 250 mm (10 inches) of annual precipitation—cluster in predictable bands around the globe. The vast majority lie in the subtropical zones between 15° and 35° latitude, both north and south of the equator. This isn't coincidence; it's atmospheric physics.

The Hadley Cell Connection

At the equator, intense solar heating causes air to rise, cool, and release moisture as heavy tropical rainfall. This dry, high-altitude air then flows poleward, descending around 30° latitude. As it sinks, it compresses and warms, its relative humidity plummeting. This descending branch of the Hadley cell creates persistent high-pressure zones—subtropical anticyclones—where cloud formation is suppressed and evaporation exceeds precipitation.

Major Desert Belts

• Northern Hemisphere (15°–35°N): Sahara (Africa), Arabian Desert (Middle East), Thar Desert (India/Pakistan), Chihuahuan and Sonoran Deserts (North America), Taklamakan and Gobi (Asia—though Gobi is also rain-shadow influenced).
• Southern Hemisphere (15°–35°S): Atacama (South America), Kalahari and Namib (Africa), Australian Outback (Great Victoria, Gibson, Simpson Deserts).

Exceptions and Modifiers

Not all subtropical zones are deserts—eastern continental margins (like Florida, Southeast Asia, eastern Brazil) receive trade wind moisture. Conversely, some deserts extend beyond 35° due to rain shadow effects (Gobi, Patagonian Desert) or cold ocean currents (Atacama, Namib). The polar deserts (Antarctica, Arctic) form through a different mechanism: extreme cold locks up moisture as ice.

Understanding this latitudinal pattern helps explain not just where deserts are, but why they're expanding poleward under climate change as Hadley cells widen—a phenomenon already observed in both hemispheres.