Washington county populations

39 supported county-equivalent records in Washington; July 1, 2025 population, 2024–2025 growth and 2025 land-area density.

Population totals use July 1, 2025 observations from PEP Vintage 2025. Change is measured since July 1, 2024. County equivalents are included, including Connecticut planning regions. Missing density is displayed as unavailable, never as zero.

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39 matching records · showing first 39
Resident population, July 1, 2025; change since July 1, 2024. PEP Vintage 2025.
PlacePopulation · 2025Change · 2024–25Growth · 2024–25People / sq. mi.
King CountyWashington · County equivalent · 530332,344,939+26,980+1.16%1,108.3
Pierce CountyWashington · County equivalent · 53053946,288+6,502+0.69%567.3
Snohomish CountyWashington · County equivalent · 53061870,656+9,586+1.11%417.3
Spokane CountyWashington · County equivalent · 53063558,344+2,859+0.51%316.5
Clark CountyWashington · County equivalent · 53011532,119+5,878+1.12%846.6
Thurston CountyWashington · County equivalent · 53067304,261+2,129+0.70%421.1
Kitsap CountyWashington · County equivalent · 53035283,374+2,646+0.94%717.2
Yakima CountyWashington · County equivalent · 53077259,185+214+0.08%60.4
Whatcom CountyWashington · County equivalent · 53073236,392+1,791+0.76%112.1
Benton CountyWashington · County equivalent · 53005221,722+2,791+1.27%130.4
Skagit CountyWashington · County equivalent · 53057132,975+725+0.55%76.9
Cowlitz CountyWashington · County equivalent · 53015114,885+1,121+0.99%100.7
Grant CountyWashington · County equivalent · 53025105,727+893+0.85%39.5
Franklin CountyWashington · County equivalent · 53021102,612+1,226+1.21%82.6
Lewis CountyWashington · County equivalent · 5304188,062+931+1.07%36.7
Island CountyWashington · County equivalent · 5302985,657-325-0.38%410.4
Chelan CountyWashington · County equivalent · 5300781,941+559+0.69%28.1
Clallam CountyWashington · County equivalent · 5300978,202+272+0.35%45.0
Grays Harbor CountyWashington · County equivalent · 5302778,144+124+0.16%41.1
Mason CountyWashington · County equivalent · 5304571,165+1,406+2.02%74.2
Walla Walla CountyWashington · County equivalent · 5307162,361+252+0.41%49.1
Stevens CountyWashington · County equivalent · 5306549,668+490+1.00%20.1
Kittitas CountyWashington · County equivalent · 5303748,803+696+1.45%21.2
Whitman CountyWashington · County equivalent · 5307548,512+649+1.36%22.5
Douglas CountyWashington · County equivalent · 5301746,473+956+2.10%25.5
Okanogan CountyWashington · County equivalent · 5304745,230+582+1.30%8.6
Jefferson CountyWashington · County equivalent · 5303133,970+79+0.23%18.8
Pacific CountyWashington · County equivalent · 5304924,357+120+0.50%26.1
Klickitat CountyWashington · County equivalent · 5303924,331+326+1.36%13.0
Asotin CountyWashington · County equivalent · 5300322,545+7+0.03%35.4
Adams CountyWashington · County equivalent · 5300121,488+166+0.78%11.2
San Juan CountyWashington · County equivalent · 5305518,577+21+0.11%106.8
Pend Oreille CountyWashington · County equivalent · 5305114,457+90+0.63%10.3
Skamania CountyWashington · County equivalent · 5305912,669+25+0.20%7.6
Lincoln CountyWashington · County equivalent · 5304311,982+155+1.31%5.2
Ferry CountyWashington · County equivalent · 530197,517-30-0.40%3.4
Wahkiakum CountyWashington · County equivalent · 530694,873+60+1.25%18.5
Columbia CountyWashington · County equivalent · 530134,141+95+2.35%4.8
Garfield CountyWashington · County equivalent · 530232,416+15+0.62%3.4

Use these comparisons consistently

A larger population does not necessarily mean faster growth. Absolute change measures the number of residents gained or lost; percentage change divides that difference by the starting population. The percentage column here covers one July-to-July interval, rather than a decade or a partial calendar year. Percent growth is suppressed where the starting population is zero.

Density divides the unrounded July 1, 2025 population by matching 2025 Gazetteer land area. It is measured in people per square mile and excludes water area. These geographic averages depend on the size and definition of each unit, so a county’s density is not directly comparable to a built-up city neighborhood.

County-equivalent names and units vary by state. Connecticut planning regions are represented in the current series; linking older county series requires a documented relationship. Incorporated places may cross county boundaries and do not form an exhaustive county breakdown.

Exports contain the current page’s visible rows after filtering, with reference date and release metadata. Use whole-dataset downloads for every row or select a compatible comparison to inspect a longer interval. The initial pep-2025-r1 snapshot remains reproducible when future releases are added.