Stay updated with real-time air quality in O'Fallon, Illinois featuring accurate data on AQI, PM2.5, PM10, O3, NO2, SO2, and CO levels. Use our interactive map and detailed forecasts to monitor pollution trends, manage health risks, and plan your daily activities with confidence.
Live AQI (Air Quality Index)
38
Good
O'Fallon, Illinois
Last updated: ... (Local time)
Good
Fine
Moderate
Poor
Very poor
Hazardous
6.74 μg/m³
0
12.1
35.5
55.5
250.5
500.5+
30.66 μg/m³
0
55
155
255
425
605+
23.99 ppb
0
55
71
86
201
201+
0.60 ppb
0
36
76
186
605
1005+
3.68 ppb
0
54
101
361
1250
2050+
0.31 ppm
0
4.5
9.5
12.5
230.5
50.5+
Pollen Level
Moderate
O'Fallon, Illinois
O'Fallon, Illinois
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AQI 38
Good
6.74μg/m³
PM2.5
30.66μg/m³
PM10
23.99ppb
O3
0.60ppb
SO2
3.68ppb
NO2
0.31ppm
CO
AQI 38
Good
6.74μg/m³
PM2.5
30.66μg/m³
PM10
23.99ppb
O3
0.60ppb
SO2
3.68ppb
NO2
0.31ppm
CO
AQI 38
Good
6.74μg/m³
PM2.5
30.49μg/m³
PM10
23.41ppb
O3
0.58ppb
SO2
3.71ppb
NO2
0.32ppm
CO
AQI 33
Good
6.07μg/m³
PM2.5
27.73μg/m³
PM10
24.51ppb
O3
0.59ppb
SO2
3.72ppb
NO2
0.32ppm
CO
AQI 33
Good
5.94μg/m³
PM2.5
27.53μg/m³
PM10
24.37ppb
O3
0.61ppb
SO2
3.71ppb
NO2
0.32ppm
CO
AQI 33
Good
6.44μg/m³
PM2.5
29.32μg/m³
PM10
26.22ppb
O3
0.57ppb
SO2
3.69ppb
NO2
0.32ppm
CO
Air quality data and pollutant measurements for Illinois, USA adhere to strict US EPA standards. The data is collected from multiple reliable sources, including satellites and ground-based monitoring stations. This data is further analyzed and enhanced using machine learning and advanced algorithms that factor in elements such as traffic and population density, ensuring accurate and reliable results.
Source: Ambee Data Sources
The air quality for O'fallon, Illinois is updated every hour.
The worst air quality in O'fallon, Illinois in the last 24 hours was observed at 09:00:00 on 2025-09-05.
In the last 24 hrs, the best air quality in O'fallon, Illinois was observed at 01:00:00 on 2025-09-06.
The current air quality in O'fallon, Illinois is 38, categorized as Good based on real-time data.
The most common pollutant in O'fallon, Illinois is PM2.5.
If the air quality in O'fallon, Illinois is poor, consider staying indoors and wearing a mask to protect yourself.
The current PM2.5 concentration at O'fallon, Illinois is 6.74 μg/m3.
The current PM10 concentration at O'fallon, Illinois is 30.659 μg/m3.
The current carbon monoxide (CO) concentration at O'fallon, Illinois is 0.314 ppm.
The current sulfur dioxide (SO2) concentration at O'fallon, Illinois is 0.603 ppb.
The current ozone (O3) concentration at O'fallon, Illinois is 23.988 ppm.
The current nitrogen dioxide (NO2) concentration at O'fallon, Illinois is 3.681 ppb.
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