• county
  • FIPS 53055
  • Largest town: Friday Harbor

San Juan County, Washington

San Juan County had 18,668 residents in the Census Vintage 2024 estimate, on 173.9 square miles of land. It ranks 32nd of 39 in Washington by population and 39th by land area.

Population
18,668
#32 of 39 in Washington · #1,894 in US
Area
173.9 sq mi
#39 of 39 in Washington · #3,035 in US
Density
107 / sq mi
#11 of 39 in Washington · #859 in US
Median household income
$86,442
#9 of 39 in Washington · #301 in US

Census Vintage 2024 estimates · SAIPE 2023 income · 2024 Gazetteer land area

San Juan County within Washington. Pin: Olympia.

Measure from here

Tools and pages that start from San Juan County

San Juan County population, land area and income

San Juan County had 18,668 residents in the Census Vintage 2024 estimate, on 173.9 square miles of land. It ranks 32nd of 39 in Washington by population and 39th by land area. That works out to 107.3 people per square mile, near the US average of 96.3, and above the national county median.

The median county-equivalent in Washington has 69,632 residents, so San Juan County has 27% of the typical county's population.

Its SAIPE 2023 median household income of $86,442 is in the top tenth among 3,143 counties with an estimate.

National rank among 3,144

Population

18,668

3144th1st

1894th of 3,144 (US)

Land area

174 sq mi

3144th1st

3035th of 3,144 (US)

Density

107.3 / sq mi

3144th1st

859th of 3,144 (US)

Median household income

$86,442

3143rd1st

301st of 3,143 (US)

Rank within Washington (39)

Population

18,668

39th1st

32nd of 39 (WA)

Land area

174 sq mi

39th1st

39th of 39 (WA)

Density

107.3 / sq mi

39th1st

11th of 39 (WA)

Median household income

$86,442

39th1st

9th of 39 (WA)

How San Juan County's population changed since 2020

San Juan County gained 842 residents between the July 2020 and July 2024 estimates, a rise of 4.7%. That ranks 14th of 39 in Washington for growth. The median Washington county changed by +3.2%, and the state as a whole by +3.0%.

Since the April 2020 estimates base, San Juan County recorded 445 births and 586 deaths, a natural change of -141. Net international migration added +138 and net domestic migration, people moving to or from other US counties, came to +946. The largest single component was domestic migration, which added 946 people.

17.8k202018.6k202118.7k202218.6k202318.7k2024
Census Vintage 2024 county estimates for July 1 of each year. The axis starts above zero so year-to-year changes are visible.

Components of change, April 2020 to July 2024

Births
445
Deaths
586
Net international migration
+138
Net domestic migration
+946
Change, July 2023 to July 2024
+63

Where San Juan County is

The Census internal point of San Juan County is at 48.507200, -123.103800. It sits in UTM zone 10N. The map shades Washington's 39 county-equivalents by population change from 2020 to 2024, darker for faster growth, with San Juan County outlined. Dots are towns of 1,000+ people with residents in it.

King County: +2.9%Thurston County: +2.3%Garfield County: +4.7%Adams County: +2.1%Kitsap County: +2.0%Mason County: +5.5%Stevens County: +5.2%Walla Walla County: -0.9%Whitman County: +1.2%Pierce County: +1.9%Benton County: +5.2%Columbia County: +1.8%Skamania County: +5.1%Douglas County: +6.4%Kittitas County: +2.9%Klickitat County: +5.7%Pacific County: +3.2%Grant County: +5.3%Grays Harbor County: +2.7%Jefferson County: +2.7%Lincoln County: +8.6%San Juan County: +4.7%Skagit County: +2.2%Island County: -0.6%Ferry County: +4.8%Chelan County: +2.4%Clark County: +4.3%Asotin County: +0.9%Franklin County: +4.2%Whatcom County: +3.3%Snohomish County: +4.1%Pend Oreille County: +6.1%Yakima County: +0.7%Clallam County: +0.8%Wahkiakum County: +7.9%Spokane County: +2.7%Okanogan County: +6.6%Cowlitz County: +2.7%Lewis County: +5.4%
Change 2020 to 2024
  1. < +1.9%
  2. < +2.7%
  3. < +4.2%
  4. < +5.3%
  5. ≥ +5.3%
no data

Orange pin: San Juan County internal point. Dark pin: Olympia.

Internal point

Decimal
48.507200, -123.103800
DMS
48°30'25.92"N 123°06'13.68"W
UTM
10N 492333.2E 5372681.1N
Geohash
c287ywqwc
Plus code
84WRGV4W+VF

Towns in San Juan County

One incorporated place of 1,000+ people has residents in San Juan County, 2,744 people together, or 15% of the county. Each figure counts only the part of the town inside San Juan County; towns marked "part" extend into another county. The largest is Friday Harbor with 2,744.

  1. 01Friday Harbor2,744
Census Vintage 2024 subcounty estimates, county parts of incorporated places (SUMLEV 157).

Counties bordering San Juan County

The Census 2024 county adjacency file lists 5 neighbors for San Juan County. The most populous is Whatcom County, WA, with 234,954 residents. Distances run between Census internal points in a straight line.

Distance to Olympia and the nearest big city

Olympia is 102.1 miles S of San Juan County's internal point in a straight line. The nearest place of 100,000 or more is Everett, WA (population 113,011), 56.3 miles away. The nearest place of 10,000 or more is Anacortes, WA (population 18,148), 22.0 miles away.

San Juan County FIPS code

The FIPS code of San Juan County is 53055: state code 53 for Washington plus county code 055. Use it as text, with the leading zero, when joining Census, BLS, or CDC county tables. SAIPE lists its 2023 median household income as $86,442.

Questions people ask

What is the population of San Juan County, Washington?

The Census Vintage 2024 estimate for July 1, 2024 is 18,668. That is up 842 people (4.7%) from the July 2020 estimate of 17,826.

What is the FIPS code of San Juan County?

53055. The first two digits (53) are Washington; the last three (055) identify the county.

What is the largest town in San Juan County?

Friday Harbor, with 2,744 residents inside San Juan County in 2024.

Which counties border San Juan County?

5 county-equivalents border it in the Census 2024 adjacency file: Whatcom County, WA; Skagit County, WA; Island County, WA; Clallam County, WA; Jefferson County, WA.

Sources and data as of

Data as of: Census Vintage 2024 population estimates, 2024 Gazetteer land area and internal points, SAIPE 2023 median household income.

  1. 01Census Vintage 2024 county population estimates
  2. 02Census 2024 Gazetteer, counties
  3. 03Census SAIPE 2023 state and county estimates
  4. 04Census Vintage 2024 subcounty population estimates
  5. 05Census 2024 county adjacency file
  6. 06Census 2024 cartographic boundary file, counties (1:5,000,000)

How every number is computed: methodology. Spotted a wrong figure? Report an error.