Do tornadoes form in dry places?

Not necessarily. Tornadoes can form in most climates, but they depend on thunderstorms in order to form, which require moisture. The most tornado-prone region in the world is located on the Great Plains of the U.S., which have a relatively dry climate, but truly arid regions rarely see tornadoes. Tornadoes are not uncommon in the southeastern U.S., which has a moist climate.

Deserts are prone to a type of whirlwind called a dust devil. Dust devils occur on sunny days and can look somewhat like tornadoes, but they are much weaker and are usually harmless.