As the baby boomer generation continues to age into retirement and birth rates slow nationwide, the U.S. population is rapidly growing older. The number of Americans older than 55 grew by 27% in the last decade, 20 times faster than the growth rate of the under 55 population, according to census data analysis. Currently, the median age in the United States is about 38. By 2060, the median age is projected to be 43.
Though the United States population as a whole is aging rapidly, there are parts of the country where a large number of young people is a defining demographic characteristic. In nearly every state, there is at least one county where the median age is below the national figure.
Using data from the U.S. Census Bureau, 24/7 Wall St. identified the youngest county or county equivalent in each state. Depending on the state, the median age in the youngest county ranges from about 22 to 41.
Many of the counties on this list are home to large colleges and universities. As the vast majority of the 19.6 million college and university students in the United States are under 25 years old, the presence of a postsecondary institution can lower the median age of any county. In places on this list like Story County, Iowa, home to Iowa State University, and Tompkins County, New York, home to Ithaca College and Cornell University, well over a quarter of the population are enrolled in college or graduate school. Here is a look at the hardest colleges to get into in every state.
A handful of other countries on this list, such as Onslow County, North Carolina, are home to several military bases and installations. Age ceilings for enlistment in the much of the U.S. armed services contributes to lower median age in these areas. Here is a look at America’s military cities.
To determine the youngest county in each state, 24/7 Wall St. reviewed five-year data on median age in each county from the U.S. Census Bureau’s 2019 American Community Survey. Counties were ranked based on the median age of all residents. In the case of a tie, the county where the largest share of the population are under age 18 ranked as the youngest.
Supplemental data on the share of the population under 18 years old and total population are five-year estimates and also came from the 2019 ACS. Data on life expectancy by county came from the 2020 County Health Rankings & Roadmaps, a joint program of the Robert Wood Johnson Foundation and University of Wisconsin Population Health Institute. Data on population and place boundaries used to determine the largest city in every county came from the Census Bureau.