Some of the largest counties in the US – particularly those on the coasts – are experiencing small declines in population, while counties in Texas dominate the list of the fastest-growing on a numeric basis, according to population estimates released by the Census Bureau.
The most populous county last year, as of July 1, was Los Angeles County, with more than 9.7 million residents. However, LA County also experienced the largest numeric decrease in population from 2021 to 2022, of close to 91,000 (a fraction of its total population). Still, no other county comes close to LA County in size, with the next-largest being Cook County in Illinois (home of Chicago), with a population of about 5.1 million. The third-largest as of July 1, 2022 was Harris County in Texas (4.78 million), followed by Maricopa County in Arizona (4.55 million) and San Diego County in California (3.28 million).
Of note, regional population shifts indicate that the most populous counties are moving to the South and West, which last year accounted for 63 of the 100 most populous counties, up from 58 in 2010 and 51 in 1990.
The Census Bureau release also identified the 10 counties with the largest numeric increase in population between 2021 and 2022. Counties in Texas occupied 6 of the top 10 spots, followed by Florida with 3 and Arizona the other. Maricopa County in Arizona was the fastest-growing in terms of numeric growth, adding 56,831 to its population, followed by Harris County in Texas (+45,626) and Collin County in Texas (+44,246).
In terms of percentage growth year-over-year, and limiting the analysis to counties with a resident population of at least 20,000, the Census Bureau finds that Whitman County in Washington was the fastest-growing last year, and the only to break the double-digit mark (+10.1%). It was followed by Kaufman County in Texas (+8.9%), Sumter County in Florida (+7.5%), Dawson County in Georgia (+5.8%) and Lumpkin County, also in Georgia (+5.8%). Not surprisingly, the counties with the biggest relative growth tended to be smaller ones, with none featuring more than 200,000 residents in 2022. For context, about one-fifth (19.5%) of US counties have a population of at least 100,000.
Turning to declines, and large counties – not surprisingly – feature on the list of those with the biggest numerical declines, led by the 2 largest counties, LA County (-90,704) and Cook County (-68,314). Rounding out the top 5 were 3 counties in New York: Queens County (-50,112), Kings County (-46,970), and Bronx County (-41,143).
Given the size of these counties (the top 4 each with at least 2.5 million residents), these declines were only a small fraction of their total population. On a percentage basis, Lassen County in California (-6%) had the largest decline, followed by 3 counties in Louisiana: St. John the Baptist Parish (-5.1%); Terrebonne Parish (-3.9%); and Plaquemines Parish (-3.3%).
The 10 counties with the largest percentage declines in population tended to be smaller ones, with only 1 having a population above 105,000. That was Bronx County in New York; its 2.9% decrease in population made it the 7th-largest by this measure.
For more, check out the Census Bureau’s release here.
