Counties in Washington by median age on 1 July (US county estimates), 2025

Jefferson County had the highest median age on 1 July (US county estimates) of 39 counties in 2025, at 61.7 years. Whitman County had the lowest, at 25.9 years. The median was 42.2 years. Source: the U.S. Census Bureau.

Highest61.7Jefferson County

Lowest25.9Whitman County

Median42.239 counties

All counties, 2025

years. Source: U.S. Census Bureau, Population Estimates Program, county population by age and sex: median age (MEDIAN_AGE_TOT) on 1 July, 2010 to 2019 from the 2010 to 2020 intercensal file and 2020 onwards from the latest vintage. Retrieved 2026-10-12.

Full ranking

Rank	Counties	2025 years	Change on 2024
1	Jefferson County	61.7	+0.3
2	San Juan County	57	+0.1
3	Pacific County	54.4	0
4	Wahkiakum County	54.1	+0.1
5	Clallam County	53.6	0
6	Columbia County	50.6	-1.1
7	Pend Oreille County	50	-0.2
8	Ferry County	49.7	+0.2
9	Skamania County	48	+0.1
10	Island County	47.5	+0.4
11	Stevens County	47.4	-0.1
12	Lincoln County	46.8	-0.3
13	Garfield County	46.5	+0.3
14	Klickitat County	46.3	0
15	Asotin County	45.9	+0.1
16	Grays Harbor County	45.2	+0.2
17	Mason County	45.1	-0.3
18	Okanogan County	43.4	-0.2
19	Skagit County	43.3	+0.1
20	Lewis County	42.2	+0.1
21	Chelan County	41.4	0
22	Cowlitz County	41.2	-0.1
23	Kitsap County	41.1	+0.2
24	Thurston County	40.7	+0.3
25	Walla Walla County	40.1	0
26	Clark County	39.8	+0.1
27	Spokane County	39.1	+0.2
27	Whatcom County	39.1	+0.1
29	Douglas County	39	-0.1
30	Snohomish County	38.8	+0.1
31	Pierce County	37.9	+0.2
32	King County	37.5	+0.1
33	Benton County	36.9	+0.1
34	Kittitas County	36.5	+0.2
35	Grant County	34.6	+0.2
35	Yakima County	34.6	+0.1
37	Franklin County	31.7	+0.2
38	Adams County	30	0
39	Whitman County	25.9	+0.1

Other periods

About this ranking

Age that divides the resident population of a US county into two halves of equal size on 1 July, from Census Bureau population estimates calculated by single year of age.

Counties only: the county file has no state or national medians, and medians cannot be added up. A single-year estimate, unlike median_age, which for US places is a five-year American Community Survey estimate.

Every value in the ranking comes from the same publisher and the same period, so the counties are compared on one definition. Equal values share a rank.

How to cite

U.S. Census Bureau. Population Estimates Program, county population by age and sex: median age (MEDIAN_AGE_TOT) on 1 July, 2010 to 2019 from the 2010 to 2020 intercensal file and 2020 onwards from the latest vintage. https://www.census.gov/programs-surveys/popest/data/data-sets.html. Retrieved 2026-10-12.

Citation styles

The publisher is the author. Invokely is named only as the place the figures were read, where a style asks for it.

APA 7

U.S. Census Bureau. (2026). Population Estimates Program, county population by age and sex: median age (MEDIAN_AGE_TOT) on 1 July, 2010 to 2019 from the 2010 to 2020 intercensal file and 2020 onwards from the latest vintage (Counties in Washington by median age on 1 July (US county estimates), 2025) [Data set]. Retrieved October 12, 2026, from https://www.census.gov/programs-surveys/popest/data/data-sets.html

MLA 9

Population Estimates Program, county population by age and sex: median age (MEDIAN_AGE_TOT) on 1 July, 2010 to 2019 from the 2010 to 2020 intercensal file and 2020 onwards from the latest vintage, Counties in Washington by median age on 1 July (US county estimates), 2025. U.S. Census Bureau, 25 June 2026, https://www.census.gov/programs-surveys/popest/data/data-sets.html. Invokely, https://invokely.ai/rankings/median-age-july-1-us-counties/washington-counties. Accessed 12 Oct. 2026.

Chicago (author-date)

U.S. Census Bureau. 2026. Population Estimates Program, county population by age and sex: median age (MEDIAN_AGE_TOT) on 1 July, 2010 to 2019 from the 2010 to 2020 intercensal file and 2020 onwards from the latest vintage. Counties in Washington by median age on 1 July (US county estimates), 2025. Dataset. Accessed October 12, 2026. https://www.census.gov/programs-surveys/popest/data/data-sets.html. Also distributed by Invokely, https://invokely.ai/rankings/median-age-july-1-us-counties/washington-counties.

Harvard

U.S. Census Bureau (2026) Population Estimates Program, county population by age and sex: median age (MEDIAN_AGE_TOT) on 1 July, 2010 to 2019 from the 2010 to 2020 intercensal file and 2020 onwards from the latest vintage, Counties in Washington by median age on 1 July (US county estimates), 2025 [Dataset]. Available at: https://www.census.gov/programs-surveys/popest/data/data-sets.html, via Invokely: https://invokely.ai/rankings/median-age-july-1-us-counties/washington-counties (Accessed: 12 October 2026).

BibTeX

@misc{census_counties_in_washington_by_2025,
  author = {{U.S. Census Bureau}},
  title = {{Population Estimates Program, county population by age and sex: median age (MEDIAN\_AGE\_TOT) on 1 July, 2010 to 2019 from the 2010 to 2020 intercensal file and 2020 onwards from the latest vintage: Counties in Washington by median age on 1 July (US county estimates), 2025}},
  year = {2026},
  howpublished = {Data set},
  url = {https://www.census.gov/programs-surveys/popest/data/data-sets.html},
  urldate = {2026-10-12},
  note = {Accessed via Invokely, https://invokely.ai/rankings/median-age-july-1-us-counties/washington-counties. Publisher attribution: U.S. Census Bureau. Population Estimates Program, county population by age and sex: median age (MEDIAN\_AGE\_TOT) on 1 July, 2010 to 2019 from the 2010 to 2020 intercensal file and 2020 onwards from the latest vintage. https://www.census.gov/programs-surveys/popest/data/data-sets.html. Retrieved 2026-10-12.},
}

RIS

TY  - DATA
AU  - U.S. Census Bureau
TI  - Population Estimates Program, county population by age and sex: median age (MEDIAN_AGE_TOT) on 1 July, 2010 to 2019 from the 2010 to 2020 intercensal file and 2020 onwards from the latest vintage: Counties in Washington by median age on 1 July (US county estimates), 2025
PY  - 2026
DA  - 2026/06/25
PB  - U.S. Census Bureau
DB  - Invokely
UR  - https://www.census.gov/programs-surveys/popest/data/data-sets.html
L2  - https://invokely.ai/rankings/median-age-july-1-us-counties/washington-counties
Y2  - 2026/10/12
N1  - Accessed via Invokely, https://invokely.ai/rankings/median-age-july-1-us-counties/washington-counties.
N1  - Publisher attribution: U.S. Census Bureau. Population Estimates Program, county population by age and sex: median age (MEDIAN_AGE_TOT) on 1 July, 2010 to 2019 from the 2010 to 2020 intercensal file and 2020 onwards from the latest vintage. https://www.census.gov/programs-surveys/popest/data/data-sets.html. Retrieved 2026-10-12.
ER  -

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Questions

Which county has the highest median age on 1 July (US county estimates)?

Jefferson County, with 61.7 years in 2025, according to the U.S. Census Bureau.

Which county has the lowest median age on 1 July (US county estimates)?

Whitman County, with 25.9 years in 2025.

Where does this ranking come from?

Every value comes from one source and one period, so the places are comparable: U.S. Census Bureau, Population Estimates Program, county population by age and sex: median age (MEDIAN_AGE_TOT) on 1 July, 2010 to 2019 from the 2010 to 2020 intercensal file and 2020 onwards from the latest vintage. Retrieved 2026-10-12.