Troy receives the higher standardized Area Score. That reflects AreaProfile's weighting, not a judgment about which place is better to live in.
Signals
Measured values
| Metric | Troy | O'Fallon | Source period |
|---|---|---|---|
| Population | 13,947 | 32,262 | 2024 ACS 5-Year |
| Median household income | $79,012 | $105,982 | 2024 ACS 5-Year |
| Per capita income | $32,005 | $54,265 | 2024 ACS 5-Year |
| Population density | 1,807/sq mi | 2,041/sq mi | 2024 ACS 5-Year |
| Median home value | $226,500 | $295,700 | 2024 ACS 5-Year |
| Median gross rent | $1,033 | $1,332 | 2024 ACS 5-Year |
| Homeownership rate | 69.9% | 70.2% | 2024 ACS 5-Year |
| Unemployment rate | 3.5% | 3.9% | June 2026 |
| Employment change (year over year) | 0.2% | -0.5% | June 2026 |
| Bachelor's degree or higher | 14.7% | 52.4% | 2024 ACS 5-Year |
| Poverty rate | 13.6% | 6.2% | 2024 ACS 5-Year |
| Housing units permitted (12 months) | 167 | 200 | 12 months ending July 2026 |
| Permits per 1,000 residents | 12.0 | 6.2 | 12 months ending July 2026 |
| Permit change (year over year) | 279.5% | -49.9% | 12 months ending July 2026 |
| Average July high | 90°F | 90°F | 1991-2020 Normals |
| Average January low | 22°F | 24°F | 1991-2020 Normals |
| Annual precipitation | 39.8" | 43.4" | 1991-2020 Normals |
| Distance to major airport | 36 mi | 21 mi | NASR current cycle |
| Average commute | 30.3 min | 25.8 min | 2024 ACS 5-Year |
| Median age | 35.2 | 37.8 | 2024 ACS 5-Year |
| Public schools | 9 | 12 | 2024-25 school year |
| Students per teacher | 13.57 | 16.15 | 2024-25 school year |
| Math proficiency | 38.3% | 36.2% | 2019-20 school year |
| Reading proficiency | 46.4% | 38.0% | 2019-20 school year |
| Free or reduced-price lunch eligibility | 29.5% | 27.4% | 2024-25 school year |
A bolded value is the more favorable of the two where the metric has a clear direction. Metrics like population and density have no inherent better or worse and are shown unweighted.
Missouri and Illinois do not give the same test. Each state writes its own assessment and sets its own passing score, so the two proficiency rows above are not directly comparable — the difference between them partly measures which standard is harder. Students per teacher and the school count are unaffected, and each profile ranks its own proficiency within its own state.
Physical risk tradeoff
Troy
Elevated or high exposure: earthquake, inland flooding.
O'Fallon
Elevated or high exposure: inland flooding.
Full profiles: Troy, MO · O'Fallon, IL · How this is calculated: methodology