Seneca Township, McHenry County, Illinois
Seneca Township is a township in McHenry County, Illinois. About 2,881 people live there (2020–2024 estimate). It covers 35.9 sq mi (92.9 km²) of land and uses Central Time. It has its own local government.
- Population, 2020–2024 estimate
- 2,881 ± 14
- County
- McHenry County
- School district
- Woodstock Community Unit School District 200
- Land area
- 35.9 sq mi (92.9 km²)
- Type
- TownshipIts own local government
- Time zone
- Central TimeUTC-06:00 in January; UTC-05:00 in July
- Median household income
- $133,558 ± $22,855
- Median home value
- $408,900 ± $55,681
- Water area
- 0.01 sq mi (0.02 km²)
- State
- Illinois
- Census code (GEOID)
- 1711168653
- Coordinates (central point)
- 42.291032, -88.525314
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 Seneca Township
- Franklinville (CDP)0 people
This place’s central point lies inside Seneca 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
- Hartland Township5.5 mi north
- Dorr Township5.7 mi east
- Marengo Township6.0 mi west
- Coral Township6.6 mi south
These towns, townships, cities and boroughs share a boundary with Seneca Township. Distances are straight lines between central points, not driving distances.
Other townships in McHenry County, largest first
- Algonquin Township88,108 people
- Grafton Township56,996 people
- McHenry Township46,965 people
- Nunda Township38,565 people
- Dorr Township21,621 people
- Greenwood Township14,581 people
- Chemung Township9,051 people
- Marengo Township7,253 people
- Richmond Township6,763 people
- Burton Township4,891 people
- Coral Township3,648 people
- Riley Township2,998 people
All 16
- Dunham Township2,777 people
- Hebron Township2,425 people
- Hartland Township1,566 people
- Alden Township1,502 people
People counts are American Community Survey 2020–2024 5-year estimates. See McHenry County for its cities, ZIP Code areas and county seat.
Sunrise and sunset in Seneca Township
- Longest day
- 15 hours 17 minutes around June 21
- Shortest day
- 9 hours 5 minutes around December 21
- Earliest sunrise
- 5:16 AM around June 15
- Latest sunrise
- 7:33 AM the day before clocks go back in November
- Earliest sunset
- 4:21 PM around December 9
- Latest sunset
- 8:34 PM around June 27
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 | 7:20 AM | 4:46 PM | 9 h 26 min |
| Feb 15 | 6:50 AM | 5:26 PM | 10 h 36 min |
| Mar 15 | 7:06 AM | 7:00 PM | 11 h 54 min |
| Apr 15 | 6:13 AM | 7:35 PM | 13 h 22 min |
| May 15 | 5:32 AM | 8:08 PM | 14 h 36 min |
| Jun 15 | 5:16 AM | 8:32 PM | 15 h 16 min |
| Jul 15 | 5:30 AM | 8:28 PM | 14 h 58 min |
| Aug 15 | 6:01 AM | 7:55 PM | 13 h 54 min |
| Sep 15 | 6:33 AM | 7:03 PM | 12 h 30 min |
| Oct 15 | 7:06 AM | 6:12 PM | 11 h 6 min |
| Nov 15 | 6:44 AM | 4:32 PM | 9 h 48 min |
| Dec 15 | 7:15 AM | 4:22 PM | 9 h 7 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 McHenry County or the local office.
Find the township or town where you are now or find your county.