According to the American Meteorological Society (AMS), a dust devil is a well-developed, but small dust whirl that tends to form for a short period of time. An average height for the weather event is roughly 200 meters, with a diameter ranging from about 3 meters to 30 meters.
“Dust devils are best developed on a hot, calm afternoon with clear skies, in a dry region when intense surface heating causes a very steep lapse rate of temperature in the lowest 100 m of the atmosphere,” AMS notes.