Legislative Services Agency released an interesting map of Iowa last week that examined the change in median age by county from 2010-18.
From 1970-2010, the median age in Iowa grew older, increasing an average of 2.3 years each decade. Population estimates since 2010 have shown little change in the median age.
There have been 46 counties that have grown younger since 2010. Fifty-one counties have grown older. Floyd and Butler have not shown any change.
Calhoun County has had the biggest change in terms of getting younger. It experienced a 4.1-year drop in median age to 43.7 years old. O’Brien, Ida, Taylor and Wayne counties all experience a change of two years or greater.
Winneshiek County gained 2.7 years to the median age, bumping up to 42.1 years old. Clayton and Emmet were the other two counties with an increase of two or more years.
According to the document, despite population increases in the older age categories since 2010, the median age has dropped in the many Iowa counties largely due to the increasing portion of the population under 40 and the decline in the 40-54 range.