What is the air quality in Saint Charles today?

The current Air Quality Index (AQI) in Saint Charles is 33 (Good). PM2.5 concentration is 7.91 µg/m³.

What is the temperature in Saint Charles right now?

The current temperature in Saint Charles is 28.5°C (feels like 31.9°C). Humidity is 57.6% and wind speed is 51.8 km/h.

Is it safe to go outside in Saint Charles?

Air quality is satisfactory. Enjoy outdoor activities. The UV Index is 2.9 (Moderate).

Air Quality in Saint Charles, United States

Windy

28.5°C · 57.6% humidity

28.5°

Feels 31.9°

Good

Air quality is satisfactory. Enjoy outdoor activities.

2 stations

Nearby Monitoring Stations

AQI Forecast

34 3pm

33 6pm

27 9pm

27 12am

24 3am

24 6am

25 9am

27 12pm

Air Quality Index Trend

43h · 6 stn

View full history →

Saint 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.

57.6%

Humidity

51.8 km/h

Wind NE

1011.6 hPa

Pressure

2.9

UV Moderate

GoodModerateUSGUnhealthyVery UnhealthyHazardous

Which pollutant is driving the AQI?

PM2.5▲

7.91 µg/m³

PM10

13.7 µg/m³

050100150200300500

What is the weather forecast for Saint Charles?

Temperature & Precipitation

PM2.5 Trend

43h · 6 stations

PM2.57.91 µg/m³ ✓ WHO

Good

PM1013.7 µg/m³

Good

UV INDEX2.9

Moderate

Station readings (2 stations within 25 km)

7.91

Median

8.15

Average

7.2

Low

9.1

High

PM2.5 µg/m³ · Model: 8.2 · Bias: +0.3

What is the 7-day forecast for Saint Charles?

07-21

32.0° 24.8°

07-22

28.5° 22.7°

07-23

21.6° 20.4°

0.38 mm

07-24

30.3° 18.9°

0.5 mm

07-25

27.7° 20.1°

4.63 mm

07-26

33.3° 25.0°

0.62 mm

07-27

31.3° 22.7°

Both models agree Avg diff: 3.5°C

Where are air quality stations near Saint Charles?

Forest Park, Missouri, USA

24.3 km PM2.5: 2.9 µg/m³

What cities are near Saint Charles?

35 Maryland Heights 38 Hazelwood 44 Saint Peters 42 Florissant 36 Overland 38 Creve Coeur 30 Chesterfield 42 Ferguson 40 Old Jamestown 44 O'Fallon

Get AQI alerts for Saint Charles

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ModerateAQI > 50 Unhealthy for Sensitive GroupsAQI > 100 UnhealthyAQI > 150 Very UnhealthyAQI > 200

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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 2026-07-21T23:17 UTC.