Total monthly cost of ownership
Cost to Own a Home in Seneca, Illinois
A $206,000 home here costs
$1,871per month, all in — with 20% down at today's 6.66% 30-year fixed rate.
A standard mortgage calculator would have told you $1,059. The real number is $812 higher every month — 77% more than the payment most buyers budget for.
Where every dollar goes
Only the first line is a mortgage payment. Change any assumption above and every figure below recalculates.
Seneca against LaSalle County and Illinois
| Measure | Seneca | LaSalle County |
|---|---|---|
| Median home value | $206,400 | $154,900 |
| Median property tax | $3,331 | $3,336 |
| Effective tax rate | 1.614% | 2.154% |
| Median gross rent | $988 | $906 |
| Population | 2,525 | 109,049 |
Seneca extends across 2 counties. Figures here use LaSalle County, where most of its housing sits.
The weather behind that power bill
Seneca sits in LaSalle County, which averages a high of 82.9°F in its hottest month and a low of 15.2°F in its coldest, with 36.19" of precipitation a year and 35% of it in a single three-month stretch. That climate drives 865 cooling and 6,211 heating degree days, which is what sets the $214 electricity line above.
See the full climate breakdown for LaSalle County — month by month temperatures, rainy season timing, snowfall and heating and cooling costs.
Other cities in LaSalle County
Full LaSalle County cost breakdown · Every county in Illinois
Common questions
How much does it cost to own a home in Seneca?
A $206,000 home in Seneca, Illinois costs approximately $1,871 per month with 20% down at 6.66%. That is $1,059 principal and interest, $277 property tax, $81 homeowners insurance, $282 utilities and $172 set aside for maintenance.
What is the property tax rate in Seneca?
Seneca has an effective property tax rate of 1.614%, based on a median home value of $206,400 and median real estate taxes of $3,331. That is lower than the LaSalle County average of 2.154%.
What is the average home price in Seneca?
The median owner-occupied home value in Seneca, Illinois is $206,400, against $154,900 across LaSalle County.
Is it cheaper to rent or buy in Seneca?
Median gross rent in Seneca is $988 a month, against $1,871 to own the median home all in. Renting costs less month to month here, though renting builds no equity.
Sources & methodology
- Median home value, real estate taxes, gross rent and population for Seneca — US Census Bureau, American Community Survey ACS 2023 5-Year, place-level tables.
- Homeowners insurance — NAIC average premium for Illinois.
- Electricity price — EIA Electric Power Monthly Table 5.6.A.
- Mortgage rate — Freddie Mac PMMS, refreshed weekly.
- Maintenance (1%/yr) and water and sewer ($68/mo) are national estimates. Every assumption above is editable.