Population by age, mapped by county
Median Age, 2010
In 2010, the median age of persons living in Washington state was 37.3 years. In 2017 the median age had increased to 38.2 years.
Jefferson County had the highest median age in 2010 at 53.9 years. By 2017, the median age in Jefferson County had reached 57.9 years.
In 2010, Whitman County, home of Washington State University, had the state's lowest median age at 24.4 years. In 2017, Whitman County still had the lowest median age at 24.2 years. Adams County was the only other county in Washington state with a median age less than 30 years in both 2010 (29.0 years and in 2017 (26.3 years).
Percent of Population Age 65 and Above, 2010
The age 65 and older population generally represents those nearing retirement.
In 2010, 12.3% of Washington State residents were 65 or above.
Jefferson County's share of the population age 65 or older was 26.3%.
Franklin County, with only 7.3%, had the lowest share of population 65 and older. Whitman County, with 9.5% was the only other county in single-digits.
Percent of Population Age 85 and Above, 2010
In 2010, 1.7 percent of Washington State residents were age 85 or above.
Garfield County's share of population age 85 or older was 4.2%, more than double the state average, and the highest of any Washington county. Columbia County (3.6%) and Clallam County (3.5%) were the only other counties with ratios above 3.0 percent.
Franklin County, with only 0.8% of residents age 85 or older, was at the other extreme.
Last modified: August 20, 2018