10,383 people (2024 Census estimate, −2.6% since 2020)
400 square miles of land · 26 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.
7 active community water systems list Winnebago County in the area they serve, reporting 8,283 people served in all (a system that crosses county lines counts its whole population).
| FOREST CITY WATER SUPPLY groundwater · local government · IA9525047 | 4,285 served |
| LAKE MILLS MUNICIPAL WATER DEPT-SOUTH groundwater · local government · IA9545044 | 2,158 served |
| BUFFALO CENTER MUNI WATER DEPT groundwater · local government · IA9506052 | 857 served |
| THOMPSON WATER WORKS groundwater · local government · IA9585017 | 499 served |
| LELAND WATER SUPPLY groundwater · local government · IA9549073 | 249 served |
| RAKE WATER SUPPLY groundwater · local government · IA9575068 | 186 served |
| ROCKY KNOLL MHP groundwater · private · IA9525601 | 49 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 20 people were held in Winnebago County's jail, in Vera's latest figure (2019), or 305 per 100,000 residents ages 15–64. In 2014 it was about 5.
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.
3 school districts have their office in Winnebago County. School taxes are usually the largest part of a property tax bill.
Spent $16.6 million — $14.4 million to run schools, about $12,578 per student, plus $1.3 million on buildings and equipment. Money in: $8.1 million local (mostly property tax), $9.2 million state, $1.3 million federal. Long-term debt: $129,000.
Spent $10.7 million — $8.5 million to run schools, about $12,708 per student, plus $1.9 million on buildings and equipment. Money in: $5.3 million local (mostly property tax), $4.7 million state, $1.2 million federal. Long-term debt: $203,000.
Spent $8.1 million — $6.7 million to run schools, about $13,963 per student, plus $610,000 on buildings and equipment. Money in: $4.8 million local (mostly property tax), $3.1 million state, $657,000 federal. Long-term debt: $2.7 million.
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 Low compared with other U.S. counties. FEMA estimates natural hazards cost Winnebago County about $9.6 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.
54 bridges in Winnebago County: 18 in good condition, 20 fair, and 16 poor (29.6%). “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.
| FM over BLUE EARTH RIVER · built 1924 | 938 vehicles a day |
| BROADWAY AVE over WINNEBAGO RIVER · built 1975 | 245 vehicles a day |
| LOCAL over DRAINAGE DITCH · built 1928 | 82 vehicles a day |
| LOCAL over DRAINAGE DITCH · built 1976 | 72 vehicles a day |
| LOCAL over BEAVER CREEK · built 1976 | 41 vehicles a day |
| LOCAL over DRAINAGE DITCH · built 1966 | 41 vehicles a day |
Source: Federal Highway Administration, National Bridge Inventory (2025 submission). Includes state, county and city bridges.
Federal grants paid for $957,857 of work in Winnebago County in fiscal 2025, about $90 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 Iowa 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 Winnebago 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 Winnebago County built: brayden.ozark@gmail.com.
More of Iowa: the state government and every county in Iowa.
Nearby counties: Hancock County (21 mi) · Faribault County, MN (23 mi) · Worth County (25 mi) · Kossuth County (26 mi) · Freeborn County, MN (28 mi) · Cerro Gordo County (32 mi).