Humid subtropical
O'Fallon, Illinois
St. Clair County, Illinois · Population 32k · 551 ft elevation
Living in O'Fallon
O'Fallon has a humid subtropical climate: hot summers (July highs around 90°F) and cold winters (January lows around 24°F).
Precipitation is wet at about 43″ a year, and it gets light snow (11″ a season).
Skies are sunny (63% of possible sunshine). Summers get sticky, with about 62 muggy days a year.
Air quality is moderate: a median AQI of 47, with about 3 unhealthy-air days in the latest year.
O'Fallon at a glance
- Population
- 32k
- Elevation
- 551 ft
- Average daily high
- 69°F60th percentile
- Average daily low
- 46°F52th percentile
- Annual precipitation
- 43″49th percentile
- Annual snowfall
- 11″47th percentile
- Sunshine hours per year
- 2,823 hrs52th percentile
- Median AQI
- 4776th percentile
- Median home value
- $274k53th percentile
- Median rent
- $1,312/mo58th percentile
- Median household income
- $103k75th percentile
- Property tax rate
- 2.10%91th percentile
- Top state income-tax rate
- 5.0%
- Sales tax (state + local)
- 8.9%
- Unemployment rate
- 3.3%
- Homes with broadband
- 94%69th percentile
- Walkability index
- 11.877th percentile
- Average commute
- 26 min
- Math proficiency (8th grade)
- 51%59th percentile
- Reading proficiency (8th grade)
- 56%
- Violent crime rate
- 140 per 100k42th percentile
- Property crime rate
- 922 per 100k
- Overall natural-hazard risk
- 9564th percentile
- Outdoor access
- 66th percentile
- Public land within 10 miles
- 0%
- Public land within 30 miles
- 1%
- Mountain relief within 30 miles
- 230 ft
Climate by month
| Month | High | Low | Precipitation | Snow | Sunshine |
|---|---|---|---|---|---|
| Jan | 43°F | 24°F | 2.6″ | 3.4″ | 155 hrs |
| Feb | 48°F | 28°F | 2.2″ | 3.3″ | 154 hrs |
| Mar | 59°F | 36°F | 3.4″ | 1.0″ | 195 hrs |
| Apr | 70°F | 46°F | 4.9″ | — | 242 hrs |
| May | 79°F | 56°F | 5.0″ | — | 275 hrs |
| Jun | 87°F | 64°F | 4.6″ | — | 327 hrs |
| Jul | 90°F | 68°F | 4.0″ | — | 339 hrs |
| Aug | 89°F | 65°F | 3.9″ | — | 318 hrs |
| Sep | 83°F | 57°F | 3.4″ | — | 272 hrs |
| Oct | 72°F | 46°F | 3.1″ | — | 224 hrs |
| Nov | 58°F | 37°F | 3.6″ | 0.6″ | 179 hrs |
| Dec | 46°F | 28°F | 2.6″ | 2.9″ | 142 hrs |
Near O'Fallon
- Shiloh, IL · 14k
- Fairview Heights, IL · 16k
- Swansea, IL · 15k
- Scott AFB, IL · 4.2k
- Lebanon, IL · 4.4k
- Caseyville, IL · 4.2k
- Belleville, IL · 42k
- Collinsville, IL · 24k
Largest places in Illinois
- Chicago, IL · 2.7M
- Aurora, IL · 180k
- Joliet, IL · 150k
- Naperville, IL · 149k
- Rockford, IL · 148k
- Elgin, IL · 114k
- Springfield, IL · 114k
- Peoria, IL · 112k
Sources: NOAA climate normals, NASA POWER, EPA air quality, U.S. Census Bureau, FEMA, FBI, EPA walkability and EDFacts. Methodology