What is the driest state in United States?

The driest state in the United States is Nevada. With an average annual precipitation of only 9 inches, Nevada receives less rainfall than any other state. This is due to its location in the rain shadow of the Sierra Nevada mountains, which block the flow of moisture from the Pacific Ocean. The state's terrain is also mostly desert, with little vegetation to hold moisture. As a result, Nevada has a very low humidity, and the air is often dry and dusty.