What Is a Trade Wind?

Trade winds are part of Earth global atmospheric circulation. Warm air rises at the equator, flows poleward at altitude, cools, and descends around 30 degrees latitude. The descending air flows back toward the equator, deflected westward by the Coriolis effect — creating the northeast trades north of the equator and the southeast trades south of it. These winds are remarkably consistent, which is why European sailors named them trade winds (from Middle English trade meaning path). They played a crucial role in the Age of Sail, powering transatlantic voyages for centuries.