Voter file loaded June 9, 2026 · figures are from that file, held as a fixed record
San Juan County, Washington has 15,063 active registered voters across 23 precincts, as of July 2026.
Party registration
Washington doesn't register voters by party, so there's no party breakdown to show. Party lean is usually inferred from primary participation; that data is in the voter file and available inside Motion51.
How San Juan County voted for president
Election results are public records.
San Juan County at a glance.
San Juan County had an estimated 18,668 residents in July 2024, the 32nd most populous of Washington's 39 counties, up 5.0% since the 2020 census. Of those, 16,398 are 18 or older, the voting-age population, and 38.0% are 65 or older. Its 15,063 active registered voters equal about 91.9% of that voting-age population.
It covers 174 square miles of land (107 people per square mile), and 85.3% of residents live outside any incorporated city or town. Its one incorporated place is Friday Harbor (2,744 residents). The American Community Survey (2020-2024) puts it at a median age of 57.0, a median household income of $84,800, 53.9% of adults 25 and older holding a bachelor's degree or higher and 78.0% of occupied homes owned by the people living in them.
In 2024, 12,939 votes were cast for president, about 78.9% of the voting-age population; the Democratic ticket took 73.7% and the Republican ticket 22.3%. The two-party margin moved from D+41.9 in 2008 to D+51.4 in 2024.
- Population (2024 estimate)
- 18,668
- Population (2020 census base)
- 17,786
- Voting-age population (18+)
- 16,398
- Active voters per 100 adults
- 91.9
- Residents 65 and older
- 38.0%
- People per square mile
- 107
- Living outside incorporated places
- 85.3%
- Land area
- 174 sq mi
- Median age
- 57.0
- Median household income
- $84,800
- Adults 25+ with a bachelor's degree
- 53.9%
- Owner-occupied homes
- 78.0%
Presidential vote, 2008–2024
| Year | Democratic | Republican | Margin | Votes cast |
|---|---|---|---|---|
| 2024 | 73.7% | 22.3% | D+51.4 | 12,939 |
| 2020 | 73.7% | 23.2% | D+50.5 | 13,197 |
| 2016 | 66.6% | 25.0% | D+41.6 | 10,589 |
| 2012 | 67.1% | 29.6% | D+37.5 | 10,345 |
| 2008 | 70.0% | 28.1% | D+41.9 | 10,531 |
Sources: U.S. Census Bureau Vintage 2024 population estimates and 2024 Gazetteer; American Community Survey 2020–2024 5-year estimates; certified county presidential returns. Growth, density and turnout are simple arithmetic on those figures.
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