The most populous cities in area code 623 are: Phoenix.
Phoenix is the capital and most populous city of the U.S. state of Arizona. With 1,563,025 people (as of 2015 ), Phoenix is the sixth most populous city nationwide, the most populous state capital in the United States, and the only state capital with a population of more than one million residents. Phoenix is the anchor of the Phoenix metropolitan area, also known as the Valley of the Sun, which in turn is a part of the Salt River Valley. The metropolitan area is the 12th largest by population in the United States, with approximately 4.3 million people as of 2010 .
Glendale / ˈ ɡ l ɛ n d eɪ l / is a city in Maricopa County, Arizona, United States, located about nine miles (14 km) northwest from Downtown Phoenix. According to the 2010 census, the population of the city is 226,721.
Peoria / p i ˈ ɔː r i ə / is a city in Maricopa and Yavapai counties in the State of Arizona. Most of the city is located in Maricopa County, while a tiny portion in the north is in Yavapai County. It is a major suburb of Phoenix. According to 2010 Census Bureau releases, the population of the city is 154,065. Peoria is currently the sixth largest city in Arizona for land area, and the ninth largest for population. It was named after Peoria, Illinois. The word "peoria" is a corruption of the Illini word for "prairie fire." It is the spring training home of the San Diego Padres and Seattle Mariners who share the Peoria Sports Complex. In July 2008, Money magazine listed Peoria in its Top 100 Places to Live.
The 623 area code lies within the Mountain Standard Time Zone (or MST). The current time in MST is 12:31 PM on Jul 11, 2020.