The most populous cities in area code 520 are: Tucson, Phoenix, Casa Grande, Nogales, and Fort Huachuca.
Other cities in the 520 area code include: Willcox, Sierra Vista, Chandler, Scottsdale, Marana, Douglas, Benson, Green Valley, San Simon, Sells, Maricopa, Chandler Heights, Florence, Eloy, Coolidge, San Manuel, Ajo, Superior, Tumacacori, Pearce, Hayden, Laveen, Yuma, Hereford, Vail, Arizona City, Gold Canyon, Bisbee, Oracle, Kearny, Huachuca City, Miami, Saint David, Mammoth, Tombstone, Elfrida, Stanfield, Winkelman, Flagstaff, Prescott, and Cornville.
Tucson is a city and the county seat of Pima County, Arizona, United States, and home to the University of Arizona. The 2010 United States Census put the population at 520,116, while the 2015 estimated population of the entire Tucson metropolitan statistical area (MSA) was 980,263. The Tucson MSA forms part of the larger Tucson-Nogales combined statistical area (CSA), with a total population of 1,010,025 as of the 2010 Census. Tucson is the second-largest populated city in Arizona behind Phoenix, both of which anchor the Arizona Sun Corridor. The city is located 108 miles (174 km) southeast of Phoenix and 60 mi (97 km) north of the U.S.–Mexico border. Tucson is the 33rd largest city and the 53rd largest metropolitan area in the United States.Major incorporated suburbs of Tucson include Oro Valley and Marana northwest of the city, Sahuarita south of the city, and South Tucson in an enclave south of downtown. Communities in the vicinity of Tucson (some within or overlapping the city limits) include Casas Adobes, Catalina Foothills, Flowing Wells, Midvale Park, Tanque Verde, Tortolita, and Vail. Towns outside the Tucson metro area include Benson to the southeast, Catalina and Oracle to the north, and Green Valley to the south.The Spanish name of the city, Tucsón [tukˈson], is derived from the O'odham Cuk Ṣon [tʃʊk ʂɔːn], meaning "(at the) base of the black [hill]", a reference to a basalt-covered hill now known as Sentinel Peak, also known as "A" Mountain. Tucson is sometimes referred to as "The Old Pueblo".
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 . In addition, Phoenix is the seat of Maricopa County and, at 517.9 square miles (1,341 km2), it is the largest city in the state, more than twice the size of Tucson and one of the largest cities in the United States. Settled in 1867 as an agricultural community near the confluence of the Salt and Gila Rivers, Phoenix incorporated as a city in 1881. Located in the northeastern reaches of the Sonoran Desert, Phoenix has a subtropical desert climate. Despite this, its canal system led to a thriving farming community, many of the original crops remaining important parts of the Phoenix economy for decades, such as alfalfa, cotton, citrus, and hay (which was important for the cattle industry). In fact, the "Five C's" (Cotton, Cattle, Citrus, Climate, and Copper), remained the driving forces of Phoenix's economy until after World War II, when high-tech industries began to move into the valley and air conditioning made residences much more comfortable in the very hot summers. The city averaged a four percent annual population growth rate over a 40-year period from the mid-1960s to the mid-2000s. This growth rate slowed during the Great Recession of 2007–09, and has rebounded slowly. Phoenix is the cultural center of the Valley of the Sun, as well as the entire state.
Casa Grande is a city in Pinal County, approximately halfway between Phoenix and Tucson in the U.S. state of Arizona. According to the 2010 census, the population of the city is 48,571. It is named after the Casa Grande Ruins National Monument, which is actually located in Coolidge. "Casa Grande" is Spanish for "big house".
The 520 area code lies within the Mountain Daylight Time Zone (or MDT). The current time in Mountain Daylight Time is 3:01 AM on Dec 20, 2022.