Counties / Illinois / St. Clair County

St. Clair County, IL

FIPS 17163 · population 253,694 · part of St. Louis, MO

$181k
Zillow home value · 2026-06
The numbers

What this county costs and earns

Everything here joins on the county FIPS code, so each figure comes from the agency that publishes it with no name matching in between.

Zillow home value
$181k
▲ 2.2% year over year
Zillow ZHVI · direct
Median asking rent
$1,321
▲ 4.7% year over year
Zillow ZORI · direct
Gross yield
8.8%
annual rent ÷ price, before costs
derived: rent × 12 ÷ price ✓
HUD 2-bed standard
$1,218
market rent is 1.08x the standard
HUD Fair Market Rent · direct
Independent price check

Do two methods point the same way?

Zillow estimates a current home value. FHFA tracks repeat mortgage transactions. Their growth rates should be read side by side, not averaged.

Both annual signals move in the same direction
FHFA five-year cumulative+51.5%not annualized · through 2025
0%ZILLOW ZHVI2026-06+2.2%FHFA HPI2025+5.3%
Annual changes use different methods and may use different periods. The comparison checks direction and magnitude; it does not create a blended estimate. Zillow county ZHVI pulled 2026-07-26; FHFA annual county HPI pulled 2026-07-28.
Owner-reported value$180k
Surveyed gross rent$1,090
Rent burden 30%+47.7%
Median year built1975
Housing composition

Who occupies the stock—and what it is

ACS 2024 5-year
12.8%vacant
115,630estimated housing units
Occupied tenure31.6% renter
owner 68.4%renter 31.6%
Structure mix77.3% single-family
Single-family 77.3%20+ units 2.9%Mobile home 4.4%Other 15.4%
ACS estimates describe the standing housing stock and occupied tenure. They do not measure current listings, transaction prices or asking rents.

Survey source: Census ACS 5-year — county housing value, tenure and stock · ACS 2024 5-year · pulled 2026-07-30. These values describe different housing universes and are not combined into gross yield.

Annual average covered jobs89,521▼ 0.5% from the prior annual release
Covered establishments4,804annual average reporting locations
Average weekly wage$1,140▲ 4.0% from the prior annual release
Largest private supersectorTrade, transportation, and utilities27.0% of disclosed private covered jobs
Local labor base

Jobs, pay and private-sector concentration

2025
0%COVERED JOBS−0.5%WEEKLY WAGE+4.0%Trade, transportation, and utilities27.0%
Annual QCEW counts cover jobs located at reporting establishments. The industry share uses disclosed private covered employment; it is not a resident-employment measure or a forecast.

Workplace source: BLS QCEW — county employment and wages · annual county employment and wages 2025 vs 2024 · pulled 2026-07-31. QCEW counts covered jobs located in the county, not employed residents or the metro score’s CES/LAUS series.

County brief

What the local evidence says

01Decision frame

St. Clair County’s decision tension is a reported 8.76% market-rent gross yield against carrying-cost uncertainty and inland-flood exposure. It merits investigation by buyers who can verify parcel taxes, insurance and leases; those relying on a simple county-level income case should be cautious. The yield is before operating costs and does not resolve property-specific flood or tax obligations.

02Housing economics

Zillow’s county 2026-06 observations report a $1,321 monthly median asking rent and a $180,981 median home value; rent increased 4.74% year over year while value increased 2.19%. That supports the stated gross-yield measure, but does not establish a property’s collected rent or net yield. HUD’s $1,218 two-bedroom FMR is a payment standard, not a market-rent estimate. The 2.03% effective property-tax rate adds a material carrying-cost item; tax bills must be checked by parcel.

03Demand & competition

Demand and buyer-competition evidence is mixed rather than conclusive. QCEW annual covered employment at county workplaces fell 0.51%; it is not resident employment, unemployment or an outlook. Trade, transportation, and utilities is the largest disclosed private supersector, not the entire economy. Tax-return migration shows a net loss of 400 households and a $4,181 lower average income for movers in than movers out. Against 3,233 total purchases, the reported investor share is 12.81%; it documents non-owner participation, but not all-cash activity or buyer demand.

04Risk & next checks

FHFA’s 2025 repeat-transaction HPI rose 5.30% annually. It aligns directionally with Zillow’s positive reading, but their periods and methods differ and must not be averaged into one appreciation rate. Modeled climate loss is 0.21% of building value per year, consistent with inland flood as the dominant hazard, not a site-specific loss forecast. Realtor.com MLS listing price, active listings, days on market, price reductions and pending ratio are not published; that prevents an assessment of visible supply, marketing time and seller concessions. Insurance quotes, vacancy, operating costs, lease comparables and property condition are also not published, preventing net-yield underwriting.

Cities & communities

Where people live within St. Clair County

Census-recognized incorporated places and CDPs that intersect this county. The list does not pretend to include every neighborhood or informal community.

Population scale

Largest Census places

ACS 2024 5-year
Belleville city41.4KO'Fallon city32.3KCollinsville city*24KEast St. Louis city18KCahokia Heights city17.1KFairview Heights city16.7KSwansea village14.7KShiloh village14.6K
Bars use total place population, not a county-share estimate. An asterisk marks a place that crosses a county line.
Official directory

35 Census places

Population
  1. 01
    Belleville cityIncorporated place
    41,370
  2. 02
    O'Fallon cityIncorporated place
    32,262
  3. 03
    Collinsville cityIncorporated place · spans 2 counties
    24,031
  4. 04
    East St. Louis cityIncorporated place
    17,999
  5. 05
    Cahokia Heights cityIncorporated place
    17,106
  6. 06
    Fairview Heights cityIncorporated place
    16,745
  7. 07
    Swansea villageIncorporated place
    14,710
  8. 08
    Shiloh villageIncorporated place
    14,572
  9. 09
    Columbia cityIncorporated place · spans 2 counties
    11,127
  10. 10
    Mascoutah cityIncorporated place
    8,816
  11. 11
    Freeburg villageIncorporated place
    4,592
  12. 12
    Lebanon cityIncorporated place
    4,474
Show 23 more places
  1. 13
    Caseyville villageIncorporated place
    4,130
  2. 14
    Millstadt villageIncorporated place
    4,008
  3. 15
    Scott AFB CDPCensus-designated place
    3,957
  4. 16
    Dupo villageIncorporated place · spans 2 counties
    3,879
  5. 17
    Smithton villageIncorporated place
    3,680
  6. 18
    New Baden villageIncorporated place · spans 2 counties
    3,463
  7. 19
    Madison cityIncorporated place · spans 2 counties
    2,900
  8. 20
    Fairmont City villageIncorporated place · spans 2 counties
    2,492
  9. 21
    New Athens villageIncorporated place
    1,933
  10. 22
    Washington Park villageIncorporated place
    1,701
  11. 23
    Marissa villageIncorporated place
    1,232
  12. 24
    Brooklyn villageIncorporated place
    729
  13. 25
    St. Libory villageIncorporated place
    559
  14. 26
    Hecker villageIncorporated place · spans 2 counties
    521
  15. 27
    Lenzburg villageIncorporated place
    428
  16. 28
    Fayetteville villageIncorporated place
    357
  17. 29
    Sauget villageIncorporated place
    307
  18. 30
    Summerfield villageIncorporated place
    248
  19. 31
    East Carondelet villageIncorporated place
    233
  20. 32
    Paderborn CDPCensus-designated place
    20
  21. 33
    Darmstadt CDPCensus-designated place
    18
  22. 34
    Floraville CDPCensus-designated place
    0
  23. 35
    Rentchler CDPCensus-designated place
    0

Population is the total place-wide ACS estimate, not an allocated county share. A place crossing a county line is labelled explicitly. Source: Census ACS 5-year — cities and communities · ACS 2024 5-year · pulled 2026-07-30.

Risk, demand and competition

The three things a price does not tell you

01
Risk & carrying costFEMA NRI + Census ACS
Dominant hazardinland flooding

0.206% of building value expected lost per year

Effective property tax2.03%

$3,665 median annual bill

02
DemandIRS SOI household flows
Net migration-400

5,735 in · 6,135 out

Arriving vs leaving income−$4,181

$58,121 arriving · $62,302 leaving

03
CompetitionHMDA financed purchases
Purchases by investors12.8%

414 of 3,233 mortgages

investorother financed
Same metro

The other counties in St. Louis, MO

A metro is an average of these. Which side of a county line a property sits on can change the tax bill, the hazard profile and the tenant pool.

CountyPopulationPriceRentYieldHazard
St. Clair County253,694$181k$1,3218.8%inland flooding
St. Louis County995,569$293k$1,4776.0%inland flooding
St. Charles County414,535$378k$1,7005.4%inland flooding
St. Louis city288,512$187k$1,3948.9%inland flooding
Madison County264,238$202k$1,1777.0%inland flooding
Jefferson County229,458$298k$1,4846.0%inland flooding
Franklin County105,950$273k$1,1565.1%inland flooding
Lincoln County63,057$319k$1,7506.6%inland flooding
Macoupin County44,350$140kn/an/ainland flooding
Bear case

What can break the county thesis

  1. Parcel-level flood insurance, repair exposure, or tax bills could erode the gross-yield case.
  2. Median asking rent may not translate into collected rent for a specific unit, and vacancy and operating costs are unpublished.
  3. Net out-migration, lower inbound mover income, and weaker covered employment could limit tenant or resale depth.
Underwriting questions

Before pricing a property

Is the reported rent an FMR-based estimate?

No. It is median asking market rent; the two-bedroom FMR is separately a HUD payment standard.

Can current MLS supply and seller concessions be evaluated?

No. Realtor.com listing price, active listings, days on market, reductions, and pending ratio are not published.

Does the labor figure measure county residents?

No. QCEW covers annual jobs at workplaces in the county, not resident employment or unemployment.