RANKING · 2000 CENSUS · 500 SHOWN OF 3,125
Youngest by median age, US counties · 2000
US counties with the youngest median age (2023 ACS). Madison County, Idaho leads at 20.7. 3,125 counties qualify in total. South Dakota carries 4 of the top 25 entries.
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RANKPLACESTATEPOPMEDIAN AGEVS 2000
UPDATED 2026-06-02 · DATA: US CENSUS BUREAU ACS 5-YEAR ESTIMATES
Frequently asked
Which county has the lowest median age?
Madison County, Idaho ranks #1 with 20.7 (2000 American Community Survey).
What are the top 5 counties by median age?
Madison County, Idaho, Todd County, South Dakota, Harrisonburg, Virginia, Williamsburg, Virginia, Radford, Virginia.
How many counties are in this ranking?
3,125 counties qualify after filtering for population minimums and data availability. The ranking covers 2000 ACS 5-year data.
How is median age measured?
Median age of all residents. Source: US Census Bureau, American Community Survey 5-year estimates (2000).