The Driest Major US Cities

Las Vegas averages about 4.2 inches of rain per year — less than one-tenth of what Miami gets.

Phoenix isn't far behind at around 7.2 inches. Both sit in the North American desert shadow, with mountain ranges to their west wringing most of the Pacific moisture before it reaches the Valley of the Sun or the Great Basin.

Dry climates mean low humidity, which most people find comfortable up to quite hot temperatures — but it also means water scarcity is a constant municipal concern, landscaping is restricted, and lightning storms kick up grass fires in the hills most summers.