The middle latitudes are the areas between 30 and 60 degrees north latitude and 30 and 60 degrees south, or, roughly, the earth's temperate zones between the tropics and the Arctic and Antarctic. The prevailing winds in the middle latitudes are the westerlies, and are often very strong. These parts of the world also see a wide variety of fast-changing weather as cold air masses from the poles and warm air masses from the tropics push up and down over them, sometimes alternating within hours of each other, especially in the roaring forties (between 40 and 50 degrees latitude in both hemispheres).
