Maricopa County remained the fastest-growing U.S. county for the third year in a row, adding 81,244 new residents in 2018, according to the U.S. Census Bureau population estimates. The county population tops 4,410,824 million. Maricopa is the fourth most populous U.S. County.
The Phoenix-Mesa-Scottsdale metropolitan area was second in population growth over 2017 adding 96,000 new residents to bring the Valley’s population to 4.86 million in 2018. Dallas-Fort Worth-Arlington, Texas, was the fastest-growing metro, adding nearly 132,000 new residents in year-over-year data.
“One interesting trend we are seeing this year is that metro areas not among the most populous are ranked in the top 10 for population growth,” said Sandra Johnson, a demographer in the Census Bureau’s Population Division. “Though no new metro areas moved into the top 10 largest areas, Phoenix, Seattle, Austin, and Orlando all experienced numeric increases in population since 2010, rivaling growth in areas with much larger populations. This trend is consistent with the overall growth we are seeing in the south and the west.”
The metro area population gain, equal to almost twice the population increase for entire states of Massachusetts and New Hampshire, was not quite enough for the Valley to move past Boston-Cambridge-Newton Massachusetts-New Hampshire metro area. Boston metro’s population grew nearly 31,000 to 4,875,390, just 17,400 people more than Phoenix’s 4,857,962 in 2018.
In the 2020 Census, Phoenix is likely to pass Boston and become the 10th largest U.S. metro area. In 2017, the Valley passed the San Francisco-Oakland-Hayward, CA, metro area to become the 11th largest U.S. metro.
According to the Census, eight of the ten fastest-growing counties were in the west. The other two were in Florida. The population estimates found that 45 percent of U.S. counties experienced no population change or population declined.
The Valley’s population spurt means on average 263 people choose to live among the 22 Valley cities every day. Individual city population estimates are due in early May.
Santa Cruz and Cochise were the only Arizona counties to lose population, and Apache, Gila, Graham and Greenlee showed no population change.
Among counties, Maricopa County was second in population growth between 2010 and 2018.
Harris County (Houston), Texas, added 604,431 new residents over the eight-year span, compared to Maricopa County’s 593,465 new residents in the same period. Harris County has a population of 4.7 million compared to Maricopa’s 4.4 million.
Population estimates are generated annually by the Census Bureau based on a variety of sources.
The numbers represent net population changes based on births, deaths, in- and out-migration.