Five Washington County cities saw increases in population from 2016 to 2017. According to the State Data Center, Washington, Kalona, Riverside, Ainsworth and West Chester had increases in population. Since 2010, each city in Washington County and the county overall has seen an uptick in population. Kalona added the most at 172 people and Washington grew by 133 people.

Overall, Washington County’s population increased by 577 people, or 2.7%. Jefferson County increased by 9.4% and Johnson County increased by 14%. Tiffin, in Johnson County, was the fastest growing city in Iowa at 72.6% growth since 2010, while North Liberty was the fourth fastest growing city with 40.4% growth and a population of 18,813. Keokuk, Iowa, Louisa, and Henry Counties all saw declines in population.