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
7.11 μg/m³
0
12.1
35.5
55.5
250.5
500.5+
22.70 μg/m³
0
55
155
255
425
605+
14.26 ppb
0
55
71
86
201
201+
0.49 ppb
0
36
76
186
605
1005+
15.59 ppb
0
54
101
361
1250
2050+
0.31 ppm
0
4.5
9.5
12.5
230.5
50.5+
Pollen Level
Low
O'Fallon, Illinois
O'Fallon, Illinois
Scroll To Air Quality MapLoading...
AQI 44
Good
8.45μg/m³
PM2.5
37.12μg/m³
PM10
19.97ppb
O3
0.78ppb
SO2
7.29ppb
NO2
0.23ppm
CO
AQI 44
Good
8.35μg/m³
PM2.5
36.64μg/m³
PM10
20.08ppb
O3
0.80ppb
SO2
7.22ppb
NO2
0.23ppm
CO
AQI 49
Good
9.13μg/m³
PM2.5
40.91μg/m³
PM10
19.76ppb
O3
0.88ppb
SO2
7.54ppb
NO2
0.24ppm
CO
AQI 49
Good
8.55μg/m³
PM2.5
37.69μg/m³
PM10
20.24ppb
O3
1.01ppb
SO2
7.36ppb
NO2
0.24ppm
CO
AQI 44
Good
8.20μg/m³
PM2.5
36.02μg/m³
PM10
20.67ppb
O3
1.05ppb
SO2
7.31ppb
NO2
0.25ppm
CO
AQI 52
Moderate
9.61μg/m³
PM2.5
42.67μg/m³
PM10
19.85ppb
O3
0.65ppb
SO2
8.10ppb
NO2
0.24ppm
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 06:00:00 on 2025-07-21.
In the last 24 hrs, the best air quality in O'fallon, Illinois was observed at 09:00:00 on 2025-07-21.
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 6.496 μg/m3.
The current PM10 concentration at O'fallon, Illinois is 19.566 μg/m3.
The current carbon monoxide (CO) concentration at O'fallon, Illinois is 0.24 ppm.
The current sulfur dioxide (SO2) concentration at O'fallon, Illinois is 0.486 ppb.
The current ozone (O3) concentration at O'fallon, Illinois is 27.36 ppm.
The current nitrogen dioxide (NO2) concentration at O'fallon, Illinois is 9.019 ppb.
All Rights Reserved © Ambee Inc. 2025