The median age rose in each of the state's 14 counties from seven years ago.
Chittenden County was the youngest, with a median age of 37.5, which was three years older than the median age in 2000.
Windsor County is the state's oldest, with a median age of 44.7.
The new Census data also show a slow rise in the number of racial minorities and Hispanics in Vermont.
The state also has a higher number of women than men.