The city of Phoenix, Arizona is the busiest for air conditioning installation in the United States. This is primarily due to the extreme heat experienced throughout the year, with temperatures often soaring above 100 degrees Fahrenheit. According to the U.S. Energy Information Administration, Phoenix has the highest average cooling degree days per year among all major U.S. cities, reaching over 3,000. This means that residents and businesses in Phoenix require more frequent and extensive air conditioning services to maintain comfortable indoor temperatures. Additionally, the city's rapid population growth and expansion into the suburbs have increased the demand for new air conditioning installations in both residential and commercial properties.