Air Quality in O'Fallon, United States
Windy
29.1°C · 52.6% humidity
29.1°
Feels 32.1°
49
Good
Air quality is satisfactory. Enjoy outdoor activities.
Calibrated model
Nearby Monitoring Stations
O'Fallon's air quality — share it
AQI Forecast
54
9am
54
54
49
12pm
50
51
32
3pm
33
33
33
6pm
27
27
27
9pm
27
27
25
12am
25
25
25
3am
25
25
25
6am
24
25
Air Quality Index Trend
35h · 3 stnO'Fallon's air quality is primarily affected by vehicle emissions and industrial activity. Seasonal wildfire smoke and weather patterns can cause periodic air quality deterioration.
52.6%
Humidity
52.2 km/h
Wind NE
1012.7 hPa
Pressure
24.9
UV Extreme
GoodModerateUSGUnhealthyVery UnhealthyHazardous
Which pollutant is driving the AQI?
PM2.5▲
11.71 µg/m³
PM10
27.4 µg/m³
050100150200300500
What is the weather forecast for O'Fallon?
Temperature & Precipitation
PM2.5 Trend
35h · 3 stationsPM2.511.71 µg/m³
✓ WHO
Good
PM1027.4 µg/m³
Good
UV INDEX24.9
Extreme
What is the 7-day forecast for O'Fallon?
07-21
30.3° 23.3°
07-22
27.5° 20.7°
07-23
20.2° 19.2°
0.88 mm
07-24
28.9° 17.7°
0.75 mm
07-25
27.0° 19.6°
3.88 mm
07-26
32.6° 24.0°
1.06 mm
07-27
28.3° 21.5°
Both models agree
Avg diff: 3.5°C
What cities are near O'Fallon?
Get AQI alerts for O'Fallon
Notify me when air quality reaches:
Free · No account · Unsubscribe any time
Data sources: AQI from ground-level monitoring stations via AQICN. Weather forecast from ECMWF (IFS & CAMS models). AQI calculated using US EPA standard. Updated 2026-07-21T17:14 UTC.