I always find this kind of stuff interesting every spring when they release yearly population estimates. Figured that based on the popularity of the geography thread earlier this year, there might be interest in this as well. City and metro estimates usually follow in May.
Iowa now has eight counties with more than 100,000 residents (and one that's very close).
Polk 515,185
Linn 231,762
Scott 175,601
Johnson 160,080
Black Hawk 132,348
Dallas 115,343
Woodbury 107,257
Story 102,498
(Dubuque 99,242)
The link for all counties in all states (state by state) is here:
www.census.gov
By comparison, California has ten counties with over 1,000,000 residents each.
Iowa now has eight counties with more than 100,000 residents (and one that's very close).
Polk 515,185
Linn 231,762
Scott 175,601
Johnson 160,080
Black Hawk 132,348
Dallas 115,343
Woodbury 107,257
Story 102,498
(Dubuque 99,242)
The link for all counties in all states (state by state) is here:

County Population Totals and Components of Change: 2020-2024
This page features county population estimates totals and components of change for years 2020-2024.
By comparison, California has ten counties with over 1,000,000 residents each.