Piatt County, Illinois
Piatt County, Illinois, has 16,791 residents (July 2025 estimate). Its county seat is Monticello. It uses Central Time and covers 439 sq mi (1,137 km²) of land.
- Resident population, July 2025
- 16,791
- Land area
- 439 sq mi (1,137 km²)
- County seat or government
- Monticello
- Time zone
- Central TimeUTC-06:00 in January; UTC-05:00 in July
- Median household income
- $94,811 ± $8,069
- Median home value
- $180,600 ± $13,539
- Median rent, with utilities
- $1,046 ± $175
- Homes lived in by their owners
- 84.8% ± 2.2 points
- County type
- County
- Metro or micro area
- Champaign-Urbana, IL metro areaOutlying county
- Water area
- 0.29 sq mi (0.75 km²)
- State
- Illinois
- County code (FIPS)
- 17147
- Coordinates (central point)
- 40.009033, -88.592355
These coordinates mark a central point for the area, not a street address. Income, home value, rent and homes lived in by their owners: U.S. Census Bureau, American Community Survey 2020–2024 5-year estimates, ± margin at 90% confidence; checked on October 13, 2026.
Time zones in Piatt County
| Time zone | Local time and UTC offset | Next clock change |
|---|---|---|
| Central TimeAmerica/Chicago | UTC-06:00 in January; UTC-05:00 in July. Enable JavaScript for the live clock. | Enable JavaScript for upcoming changes. |
Near a time-zone line, check where you are with the time-zone finder. Your phone’s setting can differ.
ZIP Code areas, largest first
- 6185314,831 people
- 618568,226 people
- 618422,620 people
- 618132,043 people
- 618181,560 people
- 619131,300 people
- 618541,299 people
- 61884973 people
- 61875846 people
- 61882777 people
- 61929672 people
- 61839558 people
16 ZIP Code areas overlap Piatt County. People counts are 2020–2024 estimates for each whole ZIP area. Mailing ZIPs can differ; check an address with USPS ZIP Code Lookup.
Official county information
We don’t have a website for this county yet. The US government’s local-office directory ↗ lists its offices. A geographic lookup cannot determine eligibility, tax liability or a court obligation.
Townships in Piatt County, largest first
- Monticello Township6,154 people
- Sangamon Township2,505 people
- Bement Township1,905 people
- Cerro Gordo Township1,687 people
- Unity Township1,468 people
- Blue Ridge Township1,307 people
- Willow Branch Township924 people
- Goose Creek Township745 people
People counts are American Community Survey 2020–2024 5-year estimates. All townships in Illinois, by county
School districts in Piatt County, largest first
- Arthur Community Unit School District 3059,809 people
- Monticello Community Unit School District 259,621 people
- Blue Ridge Community Unit School District 184,463 people
- Cerro Gordo Community Unit School District 1002,831 people
- Bement Community Unit School District 52,242 people
- DeLand-Weldon Community Unit School District 571,382 people
Districts with land in the county; a district can cross county lines. People counts are American Community Survey 2020–2024 5-year estimates. A district boundary doesn’t decide which school a student attends.
Cities, towns and communities, largest first
These areas overlap the mapped boundary; an overlap does not mean that every address belongs to both.
- Monticello, Illinois (city)6,304 people
- Bement, Illinois (village)1,792 people
- Cerro Gordo, Illinois (village)1,349 people
- Atwood, Illinois (village)1,144 people
- Mansfield, Illinois (village)866 people
- Hammond, Illinois (village)617 people
- De Land, Illinois (village)448 people
- Cisco, Illinois (village)234 people
- Ivesdale, Illinois (village)209 people
- LaPlace, Illinois (CDP)170 people
- White Heath, Illinois (CDP)163 people
Bordering areas, nearest first
Distances are straight lines between map points.
- De Witt County, Illinois20 mi northwest
- Macon County, Illinois22 mi southwest
- Champaign County, Illinois23 mi northeast
- Moultrie County, Illinois26 mi south
- Douglas County, Illinois26 mi southeast
- McLean County, Illinois36 mi north
Before using this answer on a form
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