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)
33
Good
O'Fallon, Illinois
Last updated: ... (Local time)
Good
Fine
Moderate
Poor
Very poor
Hazardous
6.10 μg/m³
0
12.1
35.5
55.5
250.5
500.5+
26.79 μg/m³
0
55
155
255
425
605+
19.80 ppb
0
55
71
86
201
201+
1.46 ppb
0
36
76
186
605
1005+
12.47 ppb
0
54
101
361
1250
2050+
0.20 ppm
0
4.5
9.5
12.5
230.5
50.5+
Pollen Level
Low
O'Fallon, Illinois
O'Fallon, Illinois
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AQI 33
Good
5.84μg/m³
PM2.5
24.63μg/m³
PM10
19.48ppb
O3
1.47ppb
SO2
12.48ppb
NO2
0.19ppm
CO
AQI 33
Good
5.84μg/m³
PM2.5
24.63μg/m³
PM10
19.48ppb
O3
1.47ppb
SO2
12.48ppb
NO2
0.19ppm
CO
AQI 27
Good
5.19μg/m³
PM2.5
27.06μg/m³
PM10
17.92ppb
O3
1.24ppb
SO2
12.69ppb
NO2
0.19ppm
CO
AQI 27
Good
5.03μg/m³
PM2.5
26.70μg/m³
PM10
18.16ppb
O3
1.33ppb
SO2
12.45ppb
NO2
0.19ppm
CO
AQI 33
Good
5.99μg/m³
PM2.5
25.06μg/m³
PM10
19.27ppb
O3
1.51ppb
SO2
12.17ppb
NO2
0.19ppm
CO
AQI 33
Good
6.08μg/m³
PM2.5
25.83μg/m³
PM10
20.57ppb
O3
1.14ppb
SO2
13.49ppb
NO2
0.19ppm
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 05:00:00 on 2025-07-16.
In the last 24 hrs, the best air quality in O'fallon, Illinois was observed at 11:00:00 on 2025-07-16.
The current air quality in O'fallon, Illinois is 33, 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 6.098 μg/m3.
The current PM10 concentration at O'fallon, Illinois is 26.785 μg/m3.
The current carbon monoxide (CO) concentration at O'fallon, Illinois is 0.204 ppm.
The current sulfur dioxide (SO2) concentration at O'fallon, Illinois is 1.463 ppb.
The current ozone (O3) concentration at O'fallon, Illinois is 19.798 ppm.
The current nitrogen dioxide (NO2) concentration at O'fallon, Illinois is 12.475 ppb.
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