City profile
O'Fallon, IL
St. Clair County · Population 32,262
O'Fallon is a town in St. Clair County, IL with about 32,262 residents and a typical home value near $296,000. It is 15 miles from St. Louis, MO, which shapes its climate, healthcare access and amenities.
Climate
Climate type
Four seasons
Winter avg
33°F
Summer avg
80°F
Sunny days / yr
205
Home prices & cost of living
Median home price
$295,700
Typical monthly housing
$2,116
Cost of living (100 = U.S.)
104
Taxes
- Property tax
- 2.07%
- State income tax (top)
- 4.95%
- Social Security
- Not taxed
- Pensions
- Not taxed
- Sales tax (state + avg. local)
- 8.86%
FEMA natural hazard risk
Relatively High · county score 95/100
Top hazards: Heat wave, Earthquake, Hail
Nearest major airport
27 mi to St. Louis Lambert International Airport (STL)
Political lean (2024 county vote)
Competitive / purple · 53% Democratic / 45% Republican
Community
Population
32,262
Black population
16.9%
County
St. Clair County
Detailed crime figures are available for our 201 hand-researched cities.
2025–2026 trends
2026 market trends
- ▸More retirees are leaving IL than arriving, mostly over cost
- ▸Home prices are still rising in 2026 — good for long-term value, less room to negotiate
- ▸Climate/cost risks to check: severe storms
Highlights
- About 32,262 residents
- Typical home value about $296,000
- 15 miles from St. Louis, MO
Trade-offs
- Scores for this place are estimated from Census data and the nearest major city
Figures are estimates from public sources (see How we match). Verify before making decisions.