The population count of Maricopa County, AZ was 4,253,913 in 2018. The population count of San Diego County, CA was 3,302,833 in 2018. The population count of Honolulu County, HI was 987,638 in 2018.
Population
Population Change
Above charts are based on data from the U.S. Census American Community Survey | ODN Dataset | API -