Stay updated with real-time air quality in St. Charles, 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)
33
Good
St. Charles, Missouri
Last updated: ... (Local time)

Good
Fine
Moderate
Poor
Very poor
Hazardous
6.08 μg/m³
0
12.1
35.5
55.5
250.5
500.5+
25.62 μg/m³
0
55
155
255
425
605+
26.35 ppb
0
55
71
86
201
201+
0.51 ppb
0
36
76
186
605
1005+
7.35 ppb
0
54
101
361
1250
2050+
0.23 ppm
0
4.5
9.5
12.5
230.5
50.5+
Pollen Level
St. Charles, Missouri
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AQI 33
Good
5.98μg/m³
PM2.5
24.45μg/m³
PM10
26.79ppb
O3
0.46ppb
SO2
7.38ppb
NO2
0.23ppm
CO
AQI 33
Good
5.87μg/m³
PM2.5
23.81μg/m³
PM10
26.90ppb
O3
0.48ppb
SO2
7.29ppb
NO2
0.23ppm
CO
AQI 33
Good
6.28μg/m³
PM2.5
26.98μg/m³
PM10
26.19ppb
O3
0.54ppb
SO2
7.17ppb
NO2
0.22ppm
CO
AQI 38
Good
6.61μg/m³
PM2.5
27.98μg/m³
PM10
26.50ppb
O3
0.55ppb
SO2
7.67ppb
NO2
0.24ppm
CO
AQI 33
Good
5.79μg/m³
PM2.5
23.88μg/m³
PM10
26.48ppb
O3
0.69ppb
SO2
6.23ppb
NO2
0.21ppm
CO
AQI 38
Good
6.97μg/m³
PM2.5
30.07μg/m³
PM10
25.64ppb
O3
0.67ppb
SO2
7.31ppb
NO2
0.21ppm
CO
The air quality data for Missouri, USA is gathered from reliable sources such as satellites and monitoring stations, adhering to US EPA guidelines. With the help of advanced algorithms and machine learning, factors like traffic and population density are analyzed to deliver accurate and dependable results.
Source: Ambee Data Sources
Air quality updates for St. Charles, Missouri are available every hour.
St. Charles, Missouri experienced its worst air quality at 03:00:00, 2026-03-06.
The best air quality in St. Charles, Missouri was observed at 01:00:00 on 2026-03-06.
The air quality in St. Charles, Missouri right now is Good, with an AQI of 33.
In St. Charles, Missouri, PM2.5 is the most frequently found pollutant.
When air quality in St. Charles, Missouri is compromised, staying indoors and wearing a mask can reduce health risks.
St. Charles, Missouri currently has a PM2.5 concentration of 6.081 μg/m3.
St. Charles, Missouri currently has a PM10 concentration of 25.624 μg/m3.
The current carbon monoxide (CO) level in St. Charles, Missouri is 0.225 ppm.
The current sulfur dioxide (SO2) concentration in St. Charles, Missouri is 0.507 ppb.
St. Charles, Missouri currently has an ozone (O3) concentration of 26.353 ppm.
The current level of nitrogen dioxide (NO2) in St. Charles, Missouri is 7.348 ppb.
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