The 2009 Census Bureau estimates indicated that Phoenix had become the nation's 12th largest metropolitan area, passing San Francisco and Riverside-San Bernardino since 2000. The census count for 2010 indicates that Phoenix remains the 14th largest metropolitan area and failed to pass either San Francisco or Riverside-San Bernardino during the decade.
Nonetheless, Phoenix grew rapidly, adding 28.9 percent to its population. The metropolitan area had 4,193,000 residents in 2010, up from 3,252,000 in 2000.
The historical core municipality of Phoenix also grew less than expected. The 2009 Census Bureau estimates placed the population at 1,570,000, having passed Philadelphia to become the nation's fifth largest municipality. The city of Phoenix has a near universal suburban form, with a land area 520 square miles, four times that of Philadelphia. The 2010 census count was far smaller than expected, at 1,446,000, up from 1,332,000 in 2000, but still well below Philadelphia's 1,526,000. The 124,000 gain was the smallest of any census period since 1940-1950, at the end of which the city had 107,000 residents. The population growth rate was 9.3 percent, the lowest percentage increase rate since the 1880-1890 census period. The city of Phoenix captured 13 percent of the metropolitan growth, down from 33 percent in the 1990-2000 census period.
Suburban population growth was much stronger, at 42.4 percent. Suburban Pima County doubled in size and its exurban municipalities experienced strong growth. The city of Maricopa grew by 4,000 percent, from 1,000 to 43,000. Casa Grande nearly doubled in size. Suburbs within the core county of Maricopa also grew quickly. Buckeye, the last urbanization for 100 miles west on Interstate 10 grew from 7,000 to 51,000. Other urban fringe or near-urban fringe municipalities also grew quickly, such as Gilbert (109,000 to 209,000), Surprise (31,000 to 117,000) and Goodyear (19,000 to 65,000). The suburbs captured 87 percent of the metropolitan area growth, up from 67 percent in the 1990s.