Worst air pollution St. Charles, today and tomorrow
Today (16 July): Air quality in St. Charles is medium. AQI and O3 are medium; PM2.5, PM10, NO2, SO2, CO, HCHO, and PM1 are good. Pollution peaks around 8:00 AM (O3: 48.6/100).
Tomorrow (17 July 2026): Air quality in St. Charles is medium. All pollutants stay as today. Pollution peaks around 7:00 AM (O3: 51.8/100). Airmine updates local air quality forecasts four times daily.
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Developed with support from the European Space Agency (ESA)’s Business Applications and Space Solutions (BASS) team
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St. Charles' air quality reflects the Missouri River valley's flat terrain west of St. Louis, with vehicle emissions from I-70 and the surrounding suburban and commercial character contributing local sources. The Missouri River corridor channels prevailing westerly winds, while summer ozone from regional agricultural and vehicle sources across the broader Midwest airshed is the primary warm-season concern and the flat river plain generally allows reasonable dispersal throughout the year.
Today - 16 July | Pollution peaks at 08:00
AQI:
Medium
48.6/100
PM2.5 (fine particles):
Good
12.9/100
PM10 (coarse particles):
Good
11.5/100
NO2 (nitrogen dioxide):
Good
2.2/100
O3 (ozone):
Medium
48.6/100
SO2 (sulfur dioxide):
Good
0.4/100
CO (carbon monoxide):
Good
0.0/100
HCHO (formaldehyde):
Good
8.4/100
PM1 (ultrafine particles):
Good
9.1/100
Levels show the poorest local air quality during the day
Tomorrow - 17 July | Pollution peaks at 07:00
AQI:
Medium
51.8/100
PM2.5 (fine particles):
Good
13.0/100
PM10 (coarse particles):
Good
7.9/100
NO2 (nitrogen dioxide):
Good
2.1/100
O3 (ozone):
Medium
51.8/100
SO2 (sulfur dioxide):
Good
0.4/100
CO (carbon monoxide):
Good
0.0/100
HCHO (formaldehyde):
Good
9.8/100
PM1 (ultrafine particles):
Good
8.5/100
Pollen forecast in St. Charles
View pollen forecastFrequently Asked Questions
Is air quality bad in St. Charles right now?
On 16 July 2026, overall air quality in St. Charles is medium. AQI is the main air quality indicator at 48.6/100. Pollution peaks around 8:00 AM (O3: 48.6/100).
Will air quality be worse tomorrow in St. Charles?
On 17 July 2026, air quality conditions in St. Charles will be similar to today, with AQI forecast at medium at 51.8/100. Pollution peaks around 7:00 AM (O3: 51.8/100).
When is air pollution at its worst in St. Charles?
Air quality in St. Charles shifts across the year. Typically, the calmest air usually arrives in winter, between planting and harvest dust events, while spring planting and autumn harvest can push particulate levels up with dust and agricultural burning. Wide-open terrain generally helps disperse pollution quickly once the wind picks up.
Are air quality levels in St. Charles based on measurements or forecasts?
It is forecasts derived by downscaling forecasts provided by EU’s Copernicus Atmosphere Monitoring Service (CAMS) by taking into account local conditions such as traffic patterns. CAMS bases its forecast on satellite measurements of particles and chemical compounds in the atmosphere. Airmine’s services were developed with support from the European Space Agency (ESA)’s Business Applications and Space Solutions (BASS) team.
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Data provided by Airmine — Last update: 16 July 2026 at 10:33 CEST (Data is updated four times daily.)
This forecast is produced independently using Airmine's own atmospheric data and models.
Unless explicitly made clear, the content on this site has not been paid for by external organisations and is Airmine's sole responsibility.
For long term forecasts and maps, see the Airmine app