18,668 people (2024 Census estimate, +4.7% since 2020)
174 square miles of land · 107 people per square mile
“Highest” and “lowest” are just order, not grades: a high rank for poverty or hazard losses means more of it. Each figure's source is in its section below.
40 active community water systems list San Juan County in the area they serve, reporting 15,062 people served in all (a system that crosses county lines counts its whole population).
| EASTSOUND WATER USERS ASSOCIATION surface water · private · WA5322170 | 3,711 served |
| FRIDAY HARBOR TOWN OF surface water · local government · WA5326595 | 3,543 served |
| ROCHE HARBOR WATER SYSTEM INC surface water · private · WA5373230 | 2,091 served |
| ROSARIO surface water · private · WA5374270 | 1,426 served |
| FISHERMAN BAY WATER ASSOCIATION groundwater · private · WA5325547 | 1,195 served |
| DOE BAY WATER USERS ASSOC surface water · private · WA5319600 | 442 served |
| OLGA WATER USERS INC surface water · private · WA5363400 | 392 served |
| WEST SOUND WATER ASSOCIATION groundwater · private · WA5345014 | 206 served |
Source: U.S. EPA Safe Drinking Water Information System (SDWIS), active community systems, . Look up any system's violations and test results with EPA's search using its ID.
About 8 people were held in San Juan County's jail, in Vera's latest figure (2021), or 78 per 100,000 residents ages 15–64. In 2016 it was about 10.
Source: Vera Institute of Justice, Incarceration Trends (built from federal Bureau of Justice Statistics jail surveys). Counties without their own jail, or that share one, may show no figure.
4 school districts have their office in San Juan County. School taxes are usually the largest part of a property tax bill.
Spent $16.5 million — $15.4 million to run schools, about $19,645 per student, plus $1 million on buildings and equipment. Money in: $4.9 million local (mostly property tax), $10 million state, $1.5 million federal. Long-term debt: $2 million.
Spent $14 million — $13 million to run schools, about $18,496 per student, plus $471,000 on buildings and equipment. Money in: $5.1 million local (mostly property tax), $9.1 million state, $1 million federal. Long-term debt: $16.8 million.
Spent $7.4 million — $6.8 million to run schools, about $29,728 per student, plus $419,000 on buildings and equipment. Money in: $2.2 million local (mostly property tax), $4.7 million state, $901,000 federal. Long-term debt: $6.6 million.
Spent $539,000 — $484,000 to run schools, about $53,778 per student, plus $46,000 on buildings and equipment. Money in: $21,000 local (mostly property tax), $402,000 state, $40,000 federal.
Source: U.S. Census Bureau, 2023 Annual Survey of School System Finances. Districts are listed by the county of their main office; some serve neighboring counties too.
Source: County Health Rankings & Roadmaps 2025 (University of Wisconsin Population Health Institute), which gathers federal data (CDC, Census, and others); measures cover different recent years. Blank lines aren't reported for small counties.
Overall risk: Very Low compared with other U.S. counties. FEMA estimates natural hazards cost San Juan County about $9.9 million a year on average in buildings, crops and lives. Ability to bounce back (community resilience): Very High; social vulnerability: Relatively High.
Source: FEMA National Risk Index (December 2025), expected annual loss. Ratings compare counties nationwide; they're estimates, not predictions.
13 bridges in San Juan County: 4 in good condition, 9 fair, and 0 poor (0.0%). “Poor” means a main part — the deck, the beams, or the supports — is rated 4 or lower on the federal 0–9 scale. It doesn't mean unsafe to drive; unsafe bridges are closed.
Source: Federal Highway Administration, National Bridge Inventory (2025 submission). Includes state, county and city bridges.
Federal grants paid for $25.7 million of work in San Juan County in fiscal 2025, about $1,447 per resident — to the county, cities, schools, hospitals, nonprofits and others.
Source: USAspending.gov, grants by place of performance, fiscal 2025 (Oct. 2024 to Sept. 2025). Search it by county to see each award.
From Grants.gov: posted grants listing county governments as eligible, soonest deadline first; research-only and overseas programs left out; list updated 2026-10-13, refreshed weekly. 62 are open in all. Cities, towns, school districts and nonprofits have their own lists there.
Registration deadlines, early voting and polling places for Washington are on the federal site vote.gov, which links to the state's official election office.
The budget, property tax rates, audits, local officials and offices for San Juan County come from the county's own records, which we haven't gathered — not gathered, never hidden. See what a full county site looks like, or ask to have San Juan County built: brayden.ozark@gmail.com.
More of Washington: the state government and every county in Washington.
Nearby counties: Island County (31 mi) · Clallam County (45 mi) · Jefferson County (52 mi) · Skagit County (59 mi) · Whatcom County (62 mi) · Kitsap County (63 mi).