469,812 people (2024 Census estimate, −0.9% since 2020)
778 square miles of land · 604 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.
25 active community water systems list Onondaga County in the area they serve, reporting 609,047 people served in all (a system that crosses county lines counts its whole population).
| OCWA surface water · public/private · NY3304336 | 350,000 served |
| SYRACUSE CITY surface water · local government · NY3304334 | 192,000 served |
| DEWITT WDS - SOUTH buys surface water · local government · NY3304343 | 16,200 served |
| CLAY WDS buys surface water · local government · NY3304344 | 16,000 served |
| DEWITT WDS - NORTH buys surface water · local government · NY3316112 | 13,600 served |
| BALDWINSVILLE VILLAGE groundwater · local government · NY3304307 | 9,200 served |
| SKANEATELES WDS buys surface water · local government · NY3304347 | 3,500 served |
| SKANEATELES VILLAGE buys surface water · local government · NY3304331 | 2,610 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 563 people were held in Onondaga County's jail, in Vera's latest figure (2026). In 2021 it was about 578.
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.
18 school districts have their office in Onondaga County. School taxes are usually the largest part of a property tax bill.
Spent $613.5 million — $514.4 million to run schools, about $27,961 per student, plus $15.5 million on buildings and equipment. Money in: $73.7 million local (mostly property tax), $447.7 million state, $102.9 million federal. Long-term debt: $291 million.
Spent $213.1 million — $196.3 million to run schools, about $24,107 per student, plus $14.1 million on buildings and equipment. Money in: $108.8 million local (mostly property tax), $92.3 million state, $18.2 million federal. Long-term debt: $13.2 million.
Spent $206.1 million — $165.3 million to run schools, about $24,252 per student, plus $8.3 million on buildings and equipment. Money in: $97.1 million local (mostly property tax), $87.1 million state, $15.8 million federal. Long-term debt: $64.7 million.
Spent $158.3 million — $113.5 million to run schools, about $20,591 per student, plus $6.4 million on buildings and equipment. Money in: $61.7 million local (mostly property tax), $59.2 million state, $9.9 million federal. Long-term debt: $61.1 million.
Spent $109.3 million — $96.1 million to run schools, about $21,534 per student, plus $10.4 million on buildings and equipment. Money in: $52.8 million local (mostly property tax), $47.9 million state, $7.4 million federal. Long-term debt: $23.7 million.
Spent $107.5 million — $93.1 million to run schools, about $22,359 per student, plus $6.9 million on buildings and equipment. Money in: $68.1 million local (mostly property tax), $32.6 million state, $2.7 million federal. Long-term debt: $52.4 million.
Spent $112.2 million — $86.2 million to run schools, about $24,654 per student, plus $9.4 million on buildings and equipment. Money in: $52.6 million local (mostly property tax), $42.1 million state, $7.6 million federal. Long-term debt: $14.7 million.
Spent $77.8 million — $62.2 million to run schools, about $24,530 per student, plus $12.2 million on buildings and equipment. Money in: $43.9 million local (mostly property tax), $20.2 million state, $3.3 million federal. Long-term debt: $16.9 million.
And 10 more.
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: Relatively Moderate compared with other U.S. counties. FEMA estimates natural hazards cost Onondaga County about $103.1 million a year on average in buildings, crops and lives. Ability to bounce back (community resilience): Very High; social vulnerability: Relatively Low.
Source: FEMA National Risk Index (December 2025), expected annual loss. Ratings compare counties nationwide; they're estimates, not predictions.
475 bridges in Onondaga County: 141 in good condition, 287 fair, and 47 poor (9.9%). “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.
| RTE I81 over EAST WASHINGTON ST EAST · built 1968 | 114,111 vehicles a day |
| RTE I690 over LODI STREET · built 1968 | 91,568 vehicles a day |
| RTE I81 over NORTH SALINA ST · built 1958 | 74,401 vehicles a day |
| RTE I690 over N CLINTON STREET · built 1968 | 68,620 vehicles a day |
| RTE I690 over 81I 81I33032049 RTE I81 · built 1968 | 68,620 vehicles a day |
| RTE I690 over 81I 81I33032046 RTE I81 · built 1968 | 59,174 vehicles a day |
Source: Federal Highway Administration, National Bridge Inventory (2025 submission). Includes state, county and city bridges.
Federal grants paid for $732.5 million of work in Onondaga County in fiscal 2025, about $1,537 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 New York 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 Onondaga 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 Onondaga County built: brayden.ozark@gmail.com.
More of New York: the state government and every county in New York.
Nearby counties: Cayuga County (19 mi) · Madison County (28 mi) · Cortland County (29 mi) · Oswego County (31 mi) · Seneca County (35 mi) · Tompkins County (41 mi).