Stay updated with real-time air quality in O'Fallon, Missouri 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, Missouri
Last updated: ... (Local time)
Good
Fine
Moderate
Poor
Very poor
Hazardous
2.25 μg/m³
0
12.1
35.5
55.5
250.5
500.5+
11.61 μg/m³
0
55
155
255
425
605+
41.19 ppb
0
55
71
86
201
201+
0.50 ppb
0
36
76
186
605
1005+
4.99 ppb
0
54
101
361
1250
2050+
0.22 ppm
0
4.5
9.5
12.5
230.5
50.5+
Pollen Level
O'Fallon, Missouri
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AQI 31
Good
4.39μg/m³
PM2.5
16.42μg/m³
PM10
33.83ppb
O3
0.65ppb
SO2
4.54ppb
NO2
0.17ppm
CO
AQI 33
Good
4.45μg/m³
PM2.5
19.54μg/m³
PM10
35.66ppb
O3
0.66ppb
SO2
4.54ppb
NO2
0.17ppm
CO
AQI 31
Good
4.40μg/m³
PM2.5
16.43μg/m³
PM10
33.83ppb
O3
0.63ppb
SO2
4.59ppb
NO2
0.17ppm
CO
AQI 31
Good
4.41μg/m³
PM2.5
16.39μg/m³
PM10
33.81ppb
O3
0.67ppb
SO2
4.57ppb
NO2
0.17ppm
CO
AQI 32
Good
4.46μg/m³
PM2.5
19.54μg/m³
PM10
35.12ppb
O3
0.68ppb
SO2
4.58ppb
NO2
0.17ppm
CO
AQI 32
Good
4.93μg/m³
PM2.5
19.01μg/m³
PM10
35.45ppb
O3
0.55ppb
SO2
5.49ppb
NO2
0.17ppm
CO
Air quality measurements for Missouri, USA meet strict US EPA standards. These measurements are collected from reliable sources, including satellites and ground-based monitoring systems. Advanced algorithms and machine learning techniques are applied to the data, factoring in variables such as traffic and population density, to ensure precision and reliability.
Source: Ambee Data Sources
Air quality data for O'fallon, Missouri is updated on an hourly basis.
The worst air quality in O'fallon, Missouri was recorded at 09:00:00 on 2025-07-17.
The best air quality in O'fallon, Missouri was recorded at 12:00:00 on 2025-07-17.
The real-time air quality index in O'fallon, Missouri is 33, currently categorized as Good.
The most common pollutant in O'fallon, Missouri is PM2.5.
If the air quality in O'fallon, Missouri is poor, limit outdoor activities and use a mask to safeguard your health.
The measured PM2.5 levels in O'fallon, Missouri at present are 5.632 μg/m3.
The current PM10 levels in O'fallon, Missouri are 18.281 μg/m3.
The current carbon monoxide (CO) level in O'fallon, Missouri is 0.21 ppm.
The current sulfur dioxide (SO2) levels in O'fallon, Missouri are 0.629 ppb.
The current ozone (O3) levels at O'fallon, Missouri is 31.385 ppm.
The current nitrogen dioxide (NO2) levels at O'fallon, Missouri is 5.557 ppb.
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