Air Quality in O'Fallon, United States

Windy
24.5°C · 57.6% humidity
24.5°
Feels 24.5°
54
Moderate
Unusually sensitive people should consider reducing prolonged outdoor exertion.
1 station

Nearby Monitoring Stations

AQI Forecast Calibrated
33 1am
33
33
54 4am
48
44
48 7am
46
64
63 10am
62
61
61 1pm
61
61
60 4pm
60
60
60 7pm
60
60
40 10pm
40
33
CAMS model adj +6
27
27
27
27
27
27
34
34
54
54
54
54
54
54
54
54
54
54
54
54
54
34
34
27
AD 728×90

Air Quality Index Trend

35h · 3 stn

O'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.

57.6%
Humidity
59.0 km/h
Wind NE
1017.8 hPa
Pressure
4.4
UV Moderate
GoodModerateUSGUnhealthyVery UnhealthyHazardous

Which pollutant is driving the AQI?

PM2.5▲
54
13.5 µg/m³
PM10
19
20.55 µg/m³
050100150200300500

What is the weather forecast for O'Fallon?

Temperature & Precipitation

PM2.5 Trend

35h · 3 stations
PM2.513.5 µg/m³ ✓ WHO
Moderate
PM1020.55 µg/m³
Good
UV INDEX4.4
Moderate
AD 300×250
Station readings (1 station within 25 km)
13.5
Median
13.5
Average
13.5
Low
13.5
High
PM2.5 µg/m³ · Model: 10.85 · Bias: -2.7

What is the 7-day forecast for O'Fallon?

08-03
28.9° 19.8°
08-04
32.9° 17.5°
08-05
33.4° 13.8°
50.0 mm
08-06
38.1° 20.5°
5.12 mm
08-07
28.3° 19.4°
08-08
36.2° 24.7°
0.56 mm
08-09
31.9° 26.0°
Both models agree Avg diff: 3.2°C

Where are air quality stations near O'Fallon?

38
East St. Louis, Illinois, USA
21.8 km PM2.5: 9.1 µg/m³

What cities are near O'Fallon?

54 Fairview Heights 54 Belleville 54 Collinsville 54 East Saint Louis 52 Granite City 33 Edwardsville 53 St. Louis 49 Lemay 48 Spanish Lake 41 University City
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Data sources: AQI from ground-level monitoring stations via AQICN. Weather forecast from ECMWF (IFS & CAMS models). AQI calculated using US EPA standard. Updated 2026-08-08T09:10 UTC.