- Phoenix is the fifth-largest city in the United States and the capital of the state of Arizona. It is located in the Sonoran Desert and has a population of over 1.7 million people. Phoenix is known for its warm climate, with extremely hot summers and mild winters. The city is a major economic and cultural center in the Southwest, with a thriving arts scene, numerous professional sports teams, and a diverse population. Phoenix is also surrounded by natural beauty, with nearby mountains and desert landscapes that attract outdoor enthusiasts.