430,462 people (2024 Census estimate, +1.8% since 2020)
877 square miles of land · 491 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.
74 active community water systems list Hillsborough County in the area they serve, reporting 300,623 people served in all (a system that crosses county lines counts its whole population).
| MANCHESTER WATER WORKS surface water · local government · NH1471010 | 123,500 served |
| PENNICHUCK WATER WORKS surface water · private · NH1621010 | 88,853 served |
| MERRIMACK VILLAGE DIST groundwater · local government · NH1531010 | 25,500 served |
| HUDSON WATER DEPT groundwater · local government · NH1201010 | 16,700 served |
| MILFORD WATER UTILITIES DEPT buys surface water · local government · NH1561010 | 9,500 served |
| LITCHFIELD buys surface water · private · NH1371010 | 6,920 served |
| PETERBOROUGH WATER WORKS groundwater · local government · NH1871010 | 4,500 served |
| GOFFSTOWN VILLAGE PCT surface water · local government · NH0911010 | 3,250 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 336 people were held in Hillsborough County's jail, in Vera's latest figure (2023), or 118 per 100,000 residents ages 15–64. In 2018 it was about 417.
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.
22 school districts have their office in Hillsborough County. School taxes are usually the largest part of a property tax bill.
Spent $237.2 million — $218.1 million to run schools, about $18,015 per student, plus $15.6 million on buildings and equipment. Money in: $102.3 million local (mostly property tax), $93.7 million state, $54.5 million federal.
Spent $262.7 million — $191.8 million to run schools, about $19,168 per student, plus $67.3 million on buildings and equipment. Money in: $116.1 million local (mostly property tax), $62.7 million state, $36 million federal. Long-term debt: $77.9 million.
Spent $81.6 million — $78.6 million to run schools, about $18,845 per student, plus $1.9 million on buildings and equipment. Money in: $60.8 million local (mostly property tax), $19.3 million state, $2.7 million federal. Long-term debt: $19.2 million.
Spent $81.7 million — $77.8 million to run schools, about $21,779 per student, plus $3.6 million on buildings and equipment. Money in: $59.6 million local (mostly property tax), $17.6 million state, $2.4 million federal. Long-term debt: $1.6 million.
Spent $60.1 million — $58.2 million to run schools, about $18,997 per student, plus $1.5 million on buildings and equipment. Money in: $41.6 million local (mostly property tax), $14.8 million state, $4.5 million federal. Long-term debt: $6.5 million.
Spent $50.8 million — $46.8 million to run schools, about $16,886 per student, plus $3.6 million on buildings and equipment. Money in: $35.3 million local (mostly property tax), $11.6 million state, $3 million federal.
Spent $45.2 million — $43.9 million to run schools, about $20,617 per student, plus $1.1 million on buildings and equipment. Money in: $31.9 million local (mostly property tax), $11.3 million state, $2.7 million federal. Long-term debt: $3.1 million.
Spent $55.7 million — $53.5 million to run schools, about $27,086 per student, plus $2.1 million on buildings and equipment. Money in: $38.5 million local (mostly property tax), $13.3 million state, $3.6 million federal. Long-term debt: $720,000.
And 14 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 Hillsborough County about $120.3 million a year on average in buildings, crops and lives. Ability to bounce back (community resilience): Relatively High; social vulnerability: Very Low.
Source: FEMA National Risk Index (December 2025), expected annual loss. Ratings compare counties nationwide; they're estimates, not predictions.
385 bridges in Hillsborough County: 201 in good condition, 153 fair, and 31 poor (8.1%). “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-293 FEE TPK over STARK WAY · built 1956 | 46,106 vehicles a day |
| FEE TPK SB over PENNICHUCK BROOK · built 1954 | 44,365 vehicles a day |
| I-293 NH 3A TPK N over BLACK BROOK · built 1956 | 24,101 vehicles a day |
| I-293 NH 3A TPK S over BLACK BROOK · built 1956 | 22,005 vehicles a day |
| SALMON STREET EB over MERRIMACK R CSX RD RAMP · built 1970 | 13,150 vehicles a day |
| US 3 over BABOOSIC BROOK · built 1933 | 13,024 vehicles a day |
Source: Federal Highway Administration, National Bridge Inventory (2025 submission). Includes state, county and city bridges.
Federal grants paid for $133.8 million of work in Hillsborough County in fiscal 2025, about $316 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 Hampshire 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 Hillsborough 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 Hillsborough County built: brayden.ozark@gmail.com.
More of New Hampshire: the state government and every county in New Hampshire.
Nearby counties: Cheshire County (27 mi) · Merrimack County (27 mi) · Rockingham County (32 mi) · Middlesex County, MA (34 mi) · Sullivan County (40 mi) · Worcester County, MA (43 mi).