1,668,956 people (2024 Census estimate, +2.5% since 2020)
818 square miles of land · 2,041 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.
98 active community water systems list Middlesex County in the area they serve, reporting 1,611,540 people served in all (a system that crosses county lines counts its whole population).
| LOWELL REGIONAL WATER UTILITY surface water · local government · MA3160000 | 120,418 served |
| CAMBRIDGE WATER DEPARTMENT surface water · local government · MA3049000 | 118,214 served |
| NEWTON WATER DEPT. (MWRA) buys surface water · local government · MA3207000 | 88,931 served |
| SOMERVILLE WATER DEPT. (MWRA) buys surface water · local government · MA3274000 | 81,045 served |
| FRAMINGHAM WATER DEPT. (MWRA) buys surface water · local government · MA3100000 | 72,362 served |
| MALDEN WATER DIVISION (MWRA) buys surface water · local government · MA3165000 | 66,263 served |
| WALTHAM WATER DEPARTMENT buys surface water · local government · MA3308000 | 65,218 served |
| MEDFORD WATER DEPT. (MWRA) buys surface water · local government · MA3176000 | 61,700 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 707 people were held in Middlesex County's jail, in Vera's latest figure (2025). In 2020 it was about 604.
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.
55 school districts have their office in Middlesex County. School taxes are usually the largest part of a property tax bill.
Spent $430.8 million — $358.8 million to run schools, about $25,220 per student, plus $61.9 million on buildings and equipment. Money in: $10.5 million local (mostly property tax), $289.4 million state, $46.1 million federal. Long-term debt: $54.1 million.
Spent $350.7 million — $335.3 million to run schools, about $27,966 per student, plus $5.7 million on buildings and equipment. Money in: $270.6 million local (mostly property tax), $71.5 million state, $11.4 million federal. Long-term debt: $233.5 million.
Spent $261.9 million — $247.8 million to run schools, about $26,171 per student, plus $6.3 million on buildings and equipment. Money in: $114.3 million local (mostly property tax), $104.5 million state, $18 million federal. Long-term debt: $47.5 million.
Spent $163.5 million — $154.6 million to run schools, about $20,955 per student, plus $2.9 million on buildings and equipment. Money in: $22.7 million local (mostly property tax), $115.2 million state, $15 million federal. Long-term debt: $16 million.
Spent $196.7 million — $186.1 million to run schools, about $26,827 per student, plus $2.7 million on buildings and equipment. Money in: $156.2 million local (mostly property tax), $42.2 million state, $6.2 million federal. Long-term debt: $131.7 million.
Spent $379.1 million — $301.7 million to run schools, about $44,724 per student, plus $65 million on buildings and equipment. Money in: $250.5 million local (mostly property tax), $56.1 million state, $13.9 million federal.
Spent $144.2 million — $140.5 million to run schools, about $22,061 per student, plus $539,000 on buildings and equipment. Money in: $39.5 million local (mostly property tax), $72.7 million state, $16 million federal. Long-term debt: $3.2 million.
Spent $138.7 million — $128.8 million to run schools, about $21,306 per student, plus $494,000 on buildings and equipment. Money in: $100.3 million local (mostly property tax), $54.1 million state, $5.2 million federal. Long-term debt: $219.8 million.
And 47 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 High compared with other U.S. counties. FEMA estimates natural hazards cost Middlesex County about $321.9 million a year on average in buildings, crops and lives. Ability to bounce back (community resilience): Very High; social vulnerability: Very Low.
Source: FEMA National Risk Index (December 2025), expected annual loss. Ratings compare counties nationwide; they're estimates, not predictions.
821 bridges in Middlesex County: 170 in good condition, 560 fair, and 91 poor (11.1%). “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.
| I 93 over I 95 /ST128 · built 1957 | 200,824 vehicles a day |
| I 95 /ST128 over RR MBTA/BMRR · built 1950 | 192,672 vehicles a day |
| I 93 over ST 16 MYST VAL PKY · built 1960 | 182,420 vehicles a day |
| I 95 ST128 over HWY QUINOBEQUIN RD · built 1950 | 142,579 vehicles a day |
| I 90 over RR CSX · built 1957 | 114,872 vehicles a day |
| ST 9 BOYLSTON ST over TR GREEN LINE D · built 1905 | 96,206 vehicles a day |
Source: Federal Highway Administration, National Bridge Inventory (2025 submission). Includes state, county and city bridges.
Federal grants paid for $2.7 billion of work in Middlesex County in fiscal 2025, about $1,675 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.
State election: Tuesday, November 3, 2026. Early voting: 2026-10-17 to 2026-10-30. Last day to register to vote: 2026-10-24. Mail ballot request deadline: 2026-10-27. Election Day: 2026-11-03. Last day for mailed ballots to arrive: 2026-11-06.
Source: Secretary of the Commonwealth, 2026 Information for Voters, p. 4 · Cambridge Election Commission, 2026 State Election guide (return deadlines) · Mass. General Laws ch. 54, sec. 93
The budget, property tax rates, audits, local officials and offices for Middlesex 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 Middlesex County built: brayden.ozark@gmail.com.
More of Massachusetts: the state government and every county in Massachusetts.
Nearby counties: Suffolk County (22 mi) · Norfolk County (24 mi) · Essex County (29 mi) · Worcester County (30 mi) · Hillsborough County, NH (34 mi) · Rockingham County, NH (38 mi).