Air Quality in Saint Charles, United States
Windy
25.9°C · 44.9% humidity
25.9°
Feels 25.9°
40
Good
Air quality is satisfactory. Enjoy outdoor activities.
1 station
Nearby Monitoring Stations
Saint Charles's air quality — share it
AQI Forecast
Calibrated
23
5pm
23
23
40
8pm
35
32
29
11pm
27
26
25
2am
25
24
24
5am
24
23
3
8am
23
23
23
11am
23
23
3
2pm
3
3
Station readings
47h ago
AQI 23
PM2.5 5.4 µg/m³ · 47h ago
Air Quality Index Trend
34h · 4 stnSaint Charles's air quality is primarily affected by vehicle emissions and industrial activity. Seasonal wildfire smoke and weather patterns can cause periodic air quality deterioration.
44.9%
Humidity
58.4 km/h
Wind NE
1017.8 hPa
Pressure
5.9
UV High
GoodModerateUSGUnhealthyVery UnhealthyHazardous
Which pollutant is driving the AQI?
PM2.5▲
9.6 µg/m³
PM10
20.55 µg/m³
050100150200300500
What is the weather forecast for Saint Charles?
Temperature & Precipitation
PM2.5 Trend
34h · 4 stationsPM2.59.6 µg/m³
✓ WHO
Good
PM1020.55 µg/m³
Good
UV INDEX5.9
High
Station readings (1 station within 25 km)
9.6
Median
9.6
Average
9.6
Low
9.6
High
PM2.5 µg/m³ · Model: 10.0 · Bias: +0.4
What is the 7-day forecast for Saint Charles?
08-03
30.6° 20.4°
08-04
35.6° 19.3°
08-05
36.9° 16.4°
11.56 mm
08-06
40.3° 20.6°
2.38 mm
08-07
33.7° 22.2°
08-08
37.4° 24.3°
1.44 mm
08-09
39.7° 25.3°
0.31 mm
Both models agree
Avg diff: 3.7°C
Where are air quality stations near Saint Charles?
55
Ladue, Missouri, USA
9
Ladue, Missouri, USA
52
Forest Park, Missouri, USA
50
Blair Street, Missouri, USA
What cities are near Saint Charles?
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Data sources: AQI from ground-level monitoring stations via AQICN. Weather forecast from ECMWF (IFS & CAMS models). AQI calculated using US EPA standard. Updated 2026-08-08T01:04 UTC.