O'Fallon Township, St. Clair County, Illinois
O'Fallon Township is a township in St. Clair County, Illinois. About 26,785 people live there (2020–2024 estimate). It covers 35.1 sq mi (90.9 km²) of land and uses Central Time. It has its own local government.
- Population, 2020–2024 estimate
- 26,785 ± 42
- County
- St. Clair County
- School districts
- O'Fallon Township High School District 2039–12 · high schoolO'Fallon Community Consolidated School District 90Pre-K to 8 · elementary
- Land area
- 35.1 sq mi (90.9 km²)
- Type
- TownshipIts own local government
- Time zone
- Central TimeUTC-06:00 in January; UTC-05:00 in July
- Median household income
- $100,136 ± $11,271
- Median home value
- $280,700 ± $11,937
- Water area
- 0.66 sq mi (1.71 km²)
- State
- Illinois
- Census code (GEOID)
- 1716355262
- Coordinates (central point)
- 38.613793, -89.864304
These coordinates mark a central point for the area, not a street address. Population, income and home value: U.S. Census Bureau, American Community Survey 2020–2024 5-year estimates, ± margin at 90% confidence; checked on October 20, 2026.
Census place in O'Fallon Township
- O'Fallon (city)32,262 people
This place’s central point lies inside O'Fallon Township. A place can reach across the line, and its government, if it has one, can be separate from the township’s.
Bordering areas, nearest first
- Lebanon Township5.3 mi east
- Shiloh Valley Township5.9 mi south
- Caseyville Township6.1 mi west
- Jarvis Township, Madison County6.1 mi north
- Mascoutah Township8.0 mi southeast
These towns, townships, cities and boroughs share a boundary with O'Fallon Township. Distances are straight lines between central points, not driving distances.
Other townships in St. Clair County, largest first
- St. Clair Township35,601 people
- Caseyville Township35,032 people
- Centreville Township19,674 people
- East St. Louis Township17,999 people
- Shiloh Valley Township12,849 people
- Mascoutah Township9,512 people
- Stookey Township9,018 people
- Canteen Township7,877 people
- Sugar Loaf Township6,779 people
- Millstadt Township6,616 people
- Freeburg Township5,006 people
- Lebanon Township4,369 people
All 20
- Smithton Township4,102 people
- New Athens Township2,633 people
- Prairie Du Long Township2,607 people
- Marissa Township1,835 people
- Fayetteville Township1,600 people
- Lenzburg Township943 people
- Engelmann Township758 people
- Stites Township729 people
People counts are American Community Survey 2020–2024 5-year estimates. See St. Clair County for its cities, ZIP Code areas and county seat.
Sunrise and sunset in O'Fallon Township
- Longest day
- 14 hours 52 minutes around June 21
- Shortest day
- 9 hours 28 minutes around December 21
- Earliest sunrise
- 5:34 AM around June 14
- Latest sunrise
- 7:31 AM the day before clocks go back in November
- Earliest sunset
- 4:37 PM around December 7
- Latest sunset
- 8:28 PM around June 28
Clocks go forward an hour on the second Sunday in March and back on the first Sunday in November, so sunrise and sunset jump an hour later in March and an hour earlier in November.
| Day | Sunrise | Sunset | Daylight |
|---|---|---|---|
| Jan 15 | 7:15 AM | 5:02 PM | 9 h 47 min |
| Feb 15 | 6:50 AM | 5:37 PM | 10 h 47 min |
| Mar 15 | 7:10 AM | 7:06 PM | 11 h 56 min |
| Apr 15 | 6:23 AM | 7:36 PM | 13 h 13 min |
| May 15 | 5:47 AM | 8:04 PM | 14 h 17 min |
| Jun 15 | 5:34 AM | 8:25 PM | 14 h 51 min |
| Jul 15 | 5:47 AM | 8:23 PM | 14 h 36 min |
| Aug 15 | 6:13 AM | 7:53 PM | 13 h 40 min |
| Sep 15 | 6:40 AM | 7:07 PM | 12 h 27 min |
| Oct 15 | 7:08 AM | 6:21 PM | 11 h 13 min |
| Nov 15 | 6:41 AM | 4:46 PM | 10 h 5 min |
| Dec 15 | 7:09 AM | 4:39 PM | 9 h 30 min |
Approximate times for a flat horizon at the central point; the days move by a day or so from year to year. Hills and weather can change what you see.
Before using this answer on a form
A township line is not always the line on your mail: a mailing address can name another town or post office, and school districts, ZIP Codes and tax districts follow their own lines. For taxes, voting or permits, check the full address with St. Clair County or the local office.
Find the township or town where you are now or find your county.