Seneca TownshipIL
A town of 2,862.
Is Seneca Township a good place to live?
Seneca Township grades B− overall, 501st of 767 graded towns in Illinois, with clear strengths and some subjects that lag. On the other side, the typical home is worth about $409K, 4.5 years of the Chicago metro’s $91K median household income. It also does better than most on health: CDC estimates put its residents' health ahead of 74% of the country. Seneca Township’s median household income is $134,000, where Illinois’ towns sit at $83,000 and U.S. towns at $80,000. The biggest park or preserve is Pleasant Valley, at 453 acres. Most errands need a car: it is less walkable than 75% of U.S. towns.
What makes Seneca Township stand out
Where Seneca Township beats most towns.
99% of working residents leave Seneca Township for work
Where Seneca Township’s working residents go each day. Line width shows the share.
Census LEHD 2023
How Seneca Township grades
Each subject compared with towns across the country (schools within Illinois), ordered by how far Seneca Township is from typical.
How TownRatings grades towns →
Moving to Seneca Township: who provides what
Who provides power, water and the rest in Seneca Township, and how to reach them.
EPA SDWIS (Oct 9, 2026) · HIFLD + EIA-861 2025 · Census 2020 ZCTAs · NCES 2024–25 · registration: vote.gov, updated Sep 12, 2025.
The data
Ordered by what stands out in Seneca Township.
Seneca Township sends most of its workers to Chicago and beyond, owes part of its health edge to its incomes and has household incomes well above the Illinois norm.
Most working residents commute out of Seneca Township
Seneca Township has 327 jobs for its 1,532 working residents: even if every job went to a resident, most would still commute out.
Most working residents leave Seneca Township for work: only 1% work in town. Seneca Township’s average trip to work is 34 minutes. Jobs based in Seneca Township grew to 327 in 2023, 59 more than in 2013.
| Seneca Township | Illinois towns | U.S. towns | |
|---|---|---|---|
| Average trip to work | 34 minutes | 26 minutes | 25 minutes |
| Working residents who work in town | 0.8% | 8.4% | 8% |
| Below the poverty line | 4.6% | 8.4% | 9.6% |
Where working residents work
Census LEHD 2023 · ACS
Seneca Township’s schools rank ahead of 74% of Illinois districts
Its public schools are run by the Marengo CHSD 154 school district. Its two schools are below. The largest public high school is Marengo High School, with 685 students.
| School | Level | Students | Letter |
|---|---|---|---|
| Westwood Elem SchoolLargest public elementary schoolGrades 1–5 | Grades 1–5 | 385 | A |
| Marengo High SchoolLargest public high schoolGrades 9–12 | Grades 9–12 | 685 | A− |
NCES · EDFacts · graded within IL on state tests and graduation
Seneca Township’s grade for health is a B+
Against the 4,196 U.S. towns with household incomes like Seneca Township’s, it is less healthy than 71%: its national edge comes with its incomes.
31% of Seneca Township adults sleep under 7 hours. Seneca Township beats the Illinois average on 4 of 32 CDC measures and trails it on 1. 18% of Seneca Township adults binge drink.
| Seneca Township | Illinois towns | U.S. towns | |
|---|---|---|---|
| Sleep under 7 hours (CDC PLACES) | 31% | 35% | 36% |
| Binge drink (CDC PLACES) | 18% | 18% | 16% |
| Obesity (CDC PLACES) | 33% | 37% | 35% |
| Frequent mental distress (CDC PLACES) | 16% | 17% | 17% |
| What stands out | Seneca Township | IL |
|---|---|---|
| Fewer adults facing food insecurity | 12.6% | 15.9% |
| Fewer adults facing a utility shut-off | 6.2% | 7.8% |
| More adults who have had cancer | 8.8% | 7.6% |
CDC PLACES 2025 · modeled estimates for adults · CMS · HRSA
Fewer young adults than Illinois overall
The median household earns $133,558, against $83,390 across Illinois, one input to its B+ for jobs and income.
Adults 18 to 34 are 14% of residents (23% statewide); adults 35 to 64 are 43% of residents (39% statewide). The median age in Seneca Township is 44.7 years. 37% of adults 25 and older have a bachelor’s degree or more, vs 38% across Illinois.
| Seneca Township | Illinois towns | U.S. towns | |
|---|---|---|---|
| Median age | 44.7 years | 40.7 years | 40.5 years |
| Bachelor’s degree or more, 25+ | 37% | 29% | 29% |
Ages · share of residents
Education · adults 25 and older
Women and men · all residents
50% women, 50% men
That’s an even split within the survey’s margin of ±6.3 points. Across Illinois, 50.6% of residents are women.
| Seneca Township | IL | U.S. | |
|---|---|---|---|
| Under 10 | 10.2% | 11.5% | 11.6% |
| 10 to 17 | 12.9% | 10.4% | 10.3% |
| 18 to 24 | 7.1% | 9.1% | 9.1% |
| 25 to 34 | 6.6% | 13.6% | 13.7% |
| 35 to 44 | 13.6% | 13.3% | 13.2% |
| 45 to 54 | 13.2% | 12.4% | 12.2% |
| 55 to 64 | 16% | 12.8% | 12.7% |
| 65 to 74 | 13.3% | 10% | 10.2% |
| 75 and older | 7.2% | 7% | 7% |
| No diploma | 12.6% | 9.5% | 10.4% |
| High school | 23.9% | 25.1% | 26% |
| Some college | 14.8% | 19.2% | 19.1% |
| Associate’s | 12% | 8.3% | 8.8% |
| Bachelor’s | 26.5% | 22.6% | 21.6% |
| Graduate | 10.2% | 15.3% | 14.1% |
U.S. Census Bureau · ACS 2020-2024 5-year estimates · in a town of 2,900, single groups can be off by several points
Seneca Township has four seasons and pleasant summers
Seneca Township has cold, snowy winters and pleasant summers. July afternoons reach 83°, January nights drop to 14° and about 31 inches of snow falls in a winter.
Typical low → high °F
NOAA U.S. Climate Normals, 1991–2020
| Seneca Township | Illinois towns | U.S. towns | |
|---|---|---|---|
| Miles of trail per square mile | 0.2 miles per square mile | 0.3 | 0.4 |
| Conserved land | 3.8% | 3.6% | 4.3% |
| Biggest places to walk | Trails | Acres |
|---|---|---|
| 1. Yonder Prairie | 1.2 mi | 72 |
| 2. Westwood Conservation Area | 0.5 mi | 63 |
| 3. Pleasant Valley | — | 453 |
Trails & parks © OpenStreetMap contributors · Conserved land: USGS PAD-US
Seneca Township faces a moderate natural-hazard risk, led by inland flooding
Expected storm and flood damage is lower than in 59% of U.S. communities. Since 2007, 3 flood insurance claims have been paid out in Seneca Township.
FEMA flood insurance claims · FEMA National Risk Index · OpenFEMA
Six Flags Great America and 30 more within 40 miles
Museums, parks, gardens and other places to visit around Seneca Township. Close and well known come first.
Big draw31 mi Theme parkSix Flags Great America3.0M visitors a year
4 mi MuseumIllinois Railway Museum
38 mi Stadium & arenaAllstate Arena
37 mi MuseumMcDonald's #1 Store Museum
31 mi TheatreAlpine Valley Music Theatre
29 mi Stadium & arenaBMO CenterPhoto credits
Six Flags Great America: Feather Better, CC BY 4.0 · Illinois Railway Museum: The original uploader was Slambo at English Wikipedia., CC BY-SA 2.0 · Allstate Arena: Nkon21, CC BY-SA 4.0 · McDonald's #1 Store Museum: Bruce Marlin, CC BY-SA 2.5 · Alpine Valley Music Theatre: chad davis, CC BY-SA 2.0 · BMO Center: SimLibrarian, CC0
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Everything we know about Seneca Township
Colleges nearby
1 within 15 miles of the center of Seneca Township
About 9 of every 100 Seneca Township residents are enrolled in college, against 6 across Illinois.
About Seneca Township
Township in Illinois, United States
Seneca Township is located in McHenry County, Illinois. As of the 2020 census, its population was 2,893 and it contained 1,102 housing units. It includes the census-designated place of Franklinville.
From Wikipedia, licensed CC BY-SA 4.0 · facts via Wikidata (CC0)
- Area
- 36 sq mi
Seneca Township’s neighbors
5 towns share a border with Seneca Township.
All 3 graded towns on its borders grade higher than its B−; Coral Township (B) is closest.
| Town | IL rank | Overall | Cost | Safety | Schools | Health |
|---|---|---|---|---|---|---|
| Seneca Township | #501 | B− | D | — | B+ | B+ |
| Coral Township | #390 | B | C− | — | A− | A− |
| Dorr Township | #138 | A | C | — | A− | B+ |
| Marengo Township | — | — | — | — | — | — |
| Hartland Township | — | — | D | — | B | B |
| Riley Township | #357 | B+ | C | — | B+ | B+ |
Hartland Township has fewer than 2,500 residents, so it gets subject grades but no overall grade. Seneca Township, Coral Township, Dorr Township, Hartland Township and Riley Township report no FBI crime data of their own. Marengo Township isn’t graded (fewer than 1,000 residents, or not enough data). Compare Seneca Township with a neighbor →
Questions about Seneca Township
Short answers, built from the data on this page.
Is Seneca Township, IL a good place to live?
Seneca Township grades B− overall, better than 46% of U.S. towns and #501 of 767 in Illinois. It grades B+ for health and B+ for schools. Cost of living is its weak spot, with a D.
Is Seneca Township, IL expensive?
Yes. Cost of living, which also weighs rents, property taxes and how many households pay 30% or more of their income for housing, grades D.