Maricopa County, AZ Nation’s Fastest-Growing County In 2016

Adding 222 people per day last year, Maricopa County, AZ has replaced Harris County, TX as the county with the nation's highest annual population growth, according to new population estimates from the U.S. Census Bureau.

After eight years at the top of the list, Maricopa County, AZ has replaced Harris County, TX as the county with the nation’s highest annual population growth, according to new population estimates from the U.S. Census Bureau. Maricopa County gained 81,360 people between July 1, 2015 and July 1, 2016, or about 222 people per day, while the nation’s second-largest population gainer, Harris County, gained 56,587 people, or about 155 people per day on average.

population growth
2016 population estimates and components of change for the nation’s metro areas and counties. (Source: U.S. Census Bureau)

Maricopa County, home to Phoenix, primarily grew through the addition of 43,189 residents from net domestic migration, a measure of how many people move to or from an area versus other parts of the U.S. The county also added 25,428 people from natural increase (more births than deaths) and 10,188 people from net international migration.

Harris County, home to Houston, saw changes in net domestic migration, going from a net gain of more than 17,000 to a net loss of more than 16,000. Despite this, Harris County had the second largest gain in population due to high natural increase (46,412) and net international migration (27,922).

“In the early 2000s, Maricopa County was in the top one or two counties by numeric growth. From 2009-2011, Maricopa County saw much lower net migration than in the years before or after, which caused the county to drop out of the top population-gaining counties,” explained Peter Borsella, a demographer in the Census Bureau’s population division. “While net international migration has not reached prior levels, net domestic migration and natural increase have continued to rise, making Maricopa County this year’s largest numeric gainer.”

In addition, Maricopa grew the fastest among the top 10 largest counties at 1.95 percent, an increase from 1.90 percent from the previous year. Harris County remained the third-largest county with 4.6 million people, and Maricopa County remained the fourth-largest county with 4.2 million people. Los Angeles County and Cook County, IL remained the largest and second-largest counties, respectively.

The statistics provide population estimates and components of change for the nation’s 382 metropolitan statistical areas, 551 micropolitan statistical areas, and 3,142 counties, as well as Puerto Rico’s metropolitan statistical areas, micropolitan statistical areas and municipios. In the coming months, the Census Bureau will release 2016 population estimates for cities and towns, as well as national, state and county population estimates by age, sex, race and Hispanic origin.

Metropolitan Statistical Area Highlights

  • The nation’s 382 metro areas contained approximately 277.1 million people in 2016, representing approximately 86 percent of the nation’s population. This was an increase of approximately 2.3 million people from 2015.
  • For the fourth year in a row, The Villages, FL, a metro area west of the Orlando-Kissimmee-Sanford metro area, was the nation’s fastest-growing metro area, with a 4.3 percent population increase between 2015 and 2016.
  • The Dallas-Fort Worth-Arlington, TX and Houston-The Woodlands-Sugar Land, TX metro areas were the two largest numeric-gaining metro areas between 2015 and 2016, increasing by more than 100,000 each.
  • Four metro areas were among both the 25 fastest growing and the 25 largest numeric gaining between 2015 and 2016: Austin-Round Rock, TX; Raleigh, NC; Orlando-Kissimmee-Sanford, FL; and Las Vegas-Henderson-Paradise, NV. For all four areas, net domestic migration was a larger component of change than either net international migration or natural increase
  • Among the 10 largest metro areas, the Chicago-Naperville-Elgin, IL-IN-WI metro area was the only metro area that did not grow in population between 2015 and 2016.

Micropolitan Statistical Area Highlights

  • The nation’s 551 micro areas contained approximately 27.7 million people in 2016, representing approximately nine percent of the nation’s population. This is an increase of approximately 16,000 people from 2015.
  • Micro areas in the West grew the most.
  • Heber, UT was the fastest-growing micro area, with an increase of 4.7 percent between 2015 and 2016. The five fastest-growing micro areas were in the West: Heber, UT; Prineville, OR; Ellensburg, WA.; Bozeman, MT; and Cedar City, UT. Among these five areas, net domestic migration was a larger component of change than either net international migration or natural increase.
  • Bozeman, MT had the largest numeric gain among micro areas between 2015 and 2016, increasing by approximately 3,800 people. Four of the five largest numeric-gaining micro areas between 2015 and 2016 were in the West: Bozeman, MT; Hilo, HI; Kalispell, MT; and Oak Harbor, WA.

To learn more about where people are leaving from and moving to, visit the Census Flows Mapper.