998,747 people (2024 Census estimate, −1.3% since 2020)
601 square miles of land · 1,662 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.
30 active community water systems list Honolulu County in the area they serve, reporting 1,119,635 people served in all (a system that crosses county lines counts its whole population).
| HNL-WINDWARD-PEARL HARBOR groundwater · local government · HI0000331 | 631,389 served |
| WAIPAHU-EWA-WAIANAE groundwater · local government · HI0000335 | 217,479 served |
| JOINT BASE PEARL HARBOR-HICKAM groundwater · federal · HI0000360 | 65,230 served |
| MILILANI groundwater · local government · HI0000367 | 50,573 served |
| SCHOFIELD BARRACKS groundwater · federal · HI0000345 | 37,920 served |
| WAHIAWA groundwater · local government · HI0000333 | 23,348 served |
| MARINE CORPS BASE HAWAII buys groundwater · federal · HI0000356 | 16,300 served |
| WAIPIO HEIGHTS groundwater · local government · HI0000334 | 11,516 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.
No county jail figure in the national data for Honolulu County — not gathered, never hidden. Some counties share a regional jail or have none.
1 school district has its office in Honolulu County. School taxes are usually the largest part of a property tax bill.
Spent $3.7 billion — $3.4 billion to run schools, about $20,056 per student, plus $280.1 million on buildings and equipment. Money in: $55.4 million local (mostly property tax), $3.7 billion state, $465.1 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: Relatively High compared with other U.S. counties. FEMA estimates natural hazards cost Honolulu County about $517.3 million a year on average in buildings, crops and lives. Ability to bounce back (community resilience): Relatively High; social vulnerability: Relatively Low.
Source: FEMA National Risk Index (December 2025), expected annual loss. Ratings compare counties nationwide; they're estimates, not predictions.
676 bridges in Honolulu County: 272 in good condition, 364 fair, and 40 poor (5.9%). “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.
| KAM HWY/KEEHI IC over KALIHI STRM /OB · built 1943 | 70,510 vehicles a day |
| Halawa IC Ramp G&H over Halawa Heights Stream · built 1971 | 58,709 vehicles a day |
| KAL HWY over NIU STRM · built 1934 | 58,500 vehicles a day |
| NIMITZ HWY over KAPALAMA CANAL (E.B) · built 1949 | 57,600 vehicles a day |
| NIMITZ HWY over NUUANU STRM (W.B.) · built 1932 | 57,600 vehicles a day |
| NIMITZ HWY over SLIP COVER #3 HON HBR · built 1952 | 57,600 vehicles a day |
Source: Federal Highway Administration, National Bridge Inventory (2025 submission). Includes state, county and city bridges.
Federal grants paid for $1.4 billion of work in Honolulu County in fiscal 2025, about $1,361 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. Mail ballots arrive: 2026-10-16. Voter service centers open: 2026-10-20 to 2026-11-03. Paper registration deadline: 2026-10-26. Last day to ask for your ballot at a different address: 2026-10-27. Election Day: 2026-11-03.
Source: Hawaii Office of Elections, 2026 General Election Voter Guide · Hawaii Office of Elections, Voting in Hawaii · Hawaii Office of Elections, Voter Service Centers and Ballot Drop Boxes
The budget, property tax rates, audits, local officials and offices for Honolulu 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 Honolulu County built: brayden.ozark@gmail.com.
More of Hawaii: the state government and every county in Hawaii.
Nearby counties: Kalawao County (81 mi) · Kauai County (104 mi) · Maui County (111 mi) · Hawaii County (216 mi) · Aleutians East Borough, AK (2344 mi) · Kodiak Island Borough, AK (2516 mi).