Hourly Weather | Today Wednesday, May 20, 2026
St. Charles, Missouri
6 PM
Cloudy Weather
70°
Feels Like 68°
20
Humidity: 56%
UV Index: 1
Wind: 8 mph
7 PM
Cloudy Weather
68°
Feels Like 66°
13
Humidity: 57%
UV Index: 1
Wind: 7 mph
8 PM
Cloudy Weather
66°
Feels Like 64°
0
Humidity: 66%
UV Index: 0
Wind: 7 mph
9 PM
Cloudy Weather
64°
Feels Like 63°
0
Humidity: 70%
UV Index: 0
Wind: 6 mph
10 PM
Cloudy Weather
64°
Feels Like 63°
0
Humidity: 75%
UV Index: 0
Wind: 6 mph
11 PM
Cloudy Night
63°
Feels Like 63°
0
Humidity: 76%
UV Index: 0
Wind: 6 mph

Hourly Air Quality Forecast - AQI (US EPA)

6 PM
33 AQI
Good air quality Dominant pollutant: O3
Details

Pollutant Concentrations:

  • PM2.5: 4.42 µg/m³
  • PM10: 4.81 µg/m³
  • O3: 0.036 ppm
  • NO2: 0.8 ppb
  • SO2: 1 ppb
  • CO: 0.11 ppm

Health Recommendations:

Air quality is considered satisfactory, and air pollution poses little or no risk.

7 PM
33 AQI
Good air quality Dominant pollutant: O3
Details

Pollutant Concentrations:

  • PM2.5: 4.71 µg/m³
  • PM10: 5.15 µg/m³
  • O3: 0.035 ppm
  • NO2: 1 ppb
  • SO2: 1.2 ppb
  • CO: 0.11 ppm

Health Recommendations:

Air quality is considered satisfactory, and air pollution poses little or no risk.

8 PM
31 AQI
Good air quality Dominant pollutant: O3
Details

Pollutant Concentrations:

  • PM2.5: 4.93 µg/m³
  • PM10: 5.4 µg/m³
  • O3: 0.034 ppm
  • NO2: 1.4 ppb
  • SO2: 1.3 ppb
  • CO: 0.11 ppm

Health Recommendations:

Air quality is considered satisfactory, and air pollution poses little or no risk.

9 PM
29 AQI
Good air quality Dominant pollutant: O3
Details

Pollutant Concentrations:

  • PM2.5: 5.06 µg/m³
  • PM10: 5.56 µg/m³
  • O3: 0.031 ppm
  • NO2: 1.6 ppb
  • SO2: 1.3 ppb
  • CO: 0.11 ppm

Health Recommendations:

Air quality is considered satisfactory, and air pollution poses little or no risk.

10 PM
27 AQI
Good air quality Dominant pollutant: O3
Details

Pollutant Concentrations:

  • PM2.5: 5.11 µg/m³
  • PM10: 5.65 µg/m³
  • O3: 0.029 ppm
  • NO2: 1.7 ppb
  • SO2: 1.2 ppb
  • CO: 0.12 ppm

Health Recommendations:

Air quality is considered satisfactory, and air pollution poses little or no risk.

11 PM
25 AQI
Good air quality Dominant pollutant: O3
Details

Pollutant Concentrations:

  • PM2.5: 5.12 µg/m³
  • PM10: 5.69 µg/m³
  • O3: 0.028 ppm
  • NO2: 1.8 ppb
  • SO2: 1.1 ppb
  • CO: 0.12 ppm

Health Recommendations:

Air quality is considered satisfactory, and air pollution poses little or no risk.