Dust devil is a whirling column of air similar to a small tornado. It is caused by the rising of an overheated layer of air near the ground. Dust devils occur most frequently in deserts, where the sun heats the air near the dry ground to a high temperature. The motion of the air as it rises can often be seen because it may carry sand and dust. The smallest dust devils can measure less than 12 feet (4 meters) high, while the largest can rise 1,000 feet (300 meters) or more above the surface.
