827,526 people (2024 Census estimate, −5.4% since 2020)
47 square miles of land · 17,726 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.
5 active community water systems list San Francisco County in the area they serve, reporting 856,393 people served in all (a system that crosses county lines counts its whole population).
| SFPUC CITY DISTRIBUTION DIVISION buys surface water · local government · CA3810011 | 848,019 served |
| TREASURE ISLAND buys surface water · federal · CA3810702 | 3,864 served |
| PRESIDIO OF SAN FRANCISCO surface water · federal · CA3810700 | 3,500 served |
| SAN FRANCISCO REGIONAL WATER SYSTEM surface water · local government · CA3810001 | 600 served |
| HHW&P MOCCASIN COMPOUND-SFPUC buys surface water · local government · CA3810003 | 410 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 1,241 people were held in San Francisco County's jail, in Vera's latest figure (2025). In 2020 it was about 851.
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.
2 school districts have their office in San Francisco County. School taxes are usually the largest part of a property tax bill.
Spent $1.3 billion — $1.1 billion to run schools, about $22,880 per student, plus $79.9 million on buildings and equipment. Money in: $786.2 million local (mostly property tax), $572.1 million state, $97.5 million federal. Long-term debt: $1.1 billion.
Spent $13.2 million — $13.2 million to run schools, about $36,381 per student. Money in: $3.6 million local (mostly property tax), $9.6 million state, $1.2 million 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 High compared with other U.S. counties. FEMA estimates natural hazards cost San Francisco County about $853.4 million a year on average in buildings, crops and lives. Ability to bounce back (community resilience): Very High; social vulnerability: Relatively Moderate.
Source: FEMA National Risk Index (December 2025), expected annual loss. Ratings compare counties nationwide; they're estimates, not predictions.
144 bridges in San Francisco County: 48 in good condition, 76 fair, and 20 poor (13.9%). “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.
| U.S. HIGHWAY 101 over CESAR CHAVEZ BLVD · built 1951 | 234,000 vehicles a day |
| NB AND SB RTE 280 over LYELL STREET · built 1964 | 170,000 vehicles a day |
| I 280 N AL LINE over 280/101 INTERCHANGE · built 1960 | 170,000 vehicles a day |
| I 280 over SAN JOSE & SICKLES AVE · built 1964 | 166,000 vehicles a day |
| 101 AND 280 over 280/101 INTERCHANGE · built 1960 | 153,800 vehicles a day |
| INTERSTATE 280 over ALEMANY BLVD · built 1966 | 132,000 vehicles a day |
Source: Federal Highway Administration, National Bridge Inventory (2025 submission). Includes state, county and city bridges.
Federal grants paid for $3.4 billion of work in San Francisco County in fiscal 2025, about $3,896 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.
General election: Tuesday, November 3, 2026. Ballots mailed; drop boxes open: 2026-10-05. Last day to register to vote: 2026-10-19. Early in-person voting: 2026-10-24 to 2026-11-03. Election Day: 2026-11-03. Last day for mailed ballots to arrive: 2026-11-10.
Source: California Secretary of State — Nov. 3, 2026 key dates · California Official Voter Information Guide — dates to remember · California Secretary of State — make a plan to vote
The budget, property tax rates, audits, local officials and offices for San Francisco 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 Francisco County built: brayden.ozark@gmail.com.
More of California: the state government and every county in California.
Nearby counties: Marin County (27 mi) · San Mateo County (42 mi) · Sonoma County (55 mi) · Contra Costa County (60 mi) · Alameda County (61 mi) · Napa County (66 mi).