Union County, Iowa Cities (2025)

7 cities

City
Rank
2025 Pop. ↓
2020 Pop.
Change
Density
Area (mi²)
Type
Creston17,2977,534-0.64%1,4065.19 City
Afton2858870-0.23%8531.01 City
Lorimor3370385-0.8%8580.43 City
Cromwell4101105-0.98%3380.30 City
Arispe59296-1.08%1830.50 City
Shannon City671730%1720.41 City
Thayer747490%3290.14 City

Union County Cities Summary

Largest City

Creston is the largest city in Union County, with a population of 7,297.

Smallest City

Thayer is the smallest city in Union County.

10 Largest Cities

There are 7 cities in Union County, Iowa.