Phoenix Weather in September

Phoenix is the hottest major city in the United States, with summer temperatures regularly exceeding 110°F and over 100 days above 100°F annually. The city's Valley of the Sun location in the Sonoran Desert and massive urban heat island make nights especially extreme — often staying above 90°F. Monsoon season from July through September brings dramatic thunderstorms and haboobs.

Excellent shoulder season — warm with fewer tourists in many destinations.