Weather for St Charles, Missouri
Current Weather
Humidity: 50%
Feels Like: 85.9°F
Wind: ENE 4 mph
Wind Gusts: 4.6 mph
Precipitation: 0 in
Cloud Cover: 25%
Visibility: 9 mi
UV Index: 4.8
Five Day Weather Forecast
Tue
H: 96°F
L: 72°F
Wed
H: 93°F
L: 68°F
Thu
H: 93°F
L: 69°F
Fri
H: 92°F
L: 70°F
Sat
H: 90°F
L: 66°F
Air Quality
Nitrogen Dioxide: 4.44 μg/m3
Sulphur Dioxide: 9.99 μg/m3
Ozone: 162 μg/m3
Astronomical
Sun Transit: 12:56 AM
Sunset: 7:08 PM
Daylight: 12 hrs 23 mins
Moon Transit: 8:54 AM
Moonset: 4:40 PM
Moon Phase: Last Quarter
Moon Illumination: 23.8%
Best Times for Fishing or Hunting
Major Periods
8:24 AM - 10:54 AM8:48 PM - 11:18 PM
Minor Periods
4:10 PM - 5:40 PM12:30 AM - 2:00 AM
Action Rating: 2 out of 5
Air Quality Alert issued September 15 at 1:53PM CDT by NWS St Louis MO
Non-Weather Emergency Message. Not sent to IPAWS.
Effective: Mon September 15, 2025, 1:53 PM
Expires: Tue September 16, 2025, 2:00 PM
The St. Louis Clean Air Partnership has issued an air quality alert for the St. Louis metropolitan area until 8 PM CDT this evening. An Orange air quality forecast means that maximum ozone concentrations are expected to reach levels that pose a health risk. Adverse health effects increase as air quality deteriorates. Ground- level ozone is an air contaminant which can cause breathing difficulties for children, older adults, as well as persons with respiratory problems. Reducing outdoor physical activity is recommended. If it is a regularly scheduled work day you are urged to consider telecommuting, carpooling, or utilizing public transit. Avoid excessive idling and do not top off when refueling motor vehicles. The use of gasoline-powered lawn equipment should be reduced or postponed until late in the day. For more information visit the St. Louis Clean Air Partnership at http://cleanair-stlouis.com/ For current Air Quality Index (AQI) values visit https://www.airnow.gov/
Air Quality Alert issued September 15 at 8:04PM CDT by NWS St Louis MO
Non-Weather Emergency Message. Not sent to IPAWS.
Effective: Mon September 15, 2025, 8:04 PM
Expires: Tue September 16, 2025, 8:15 PM
The St. Louis Clean Air Partnership has issued an air quality alert for the St. Louis metropolitan area from 10 AM to 8 PM CDT Tuesday. An Orange air quality forecast means that maximum ozone concentrations are expected to reach levels that pose a health risk. Adverse health effects increase as air quality deteriorates. Ground- level ozone is an air contaminant which can cause breathing difficulties for children, older adults, as well as persons with respiratory problems. Reducing outdoor physical activity is recommended. If it is a regularly scheduled work day you are urged to consider telecommuting, carpooling, or utilizing public transit. Avoid excessive idling and do not top off when refueling motor vehicles. The use of gasoline-powered lawn equipment should be reduced or postponed until late in the day. For more information visit the St. Louis Clean Air Partnership at http://cleanair-stlouis.com/ For current Air Quality Index (AQI) values visit https://www.airnow.gov/
Air Quality Alert issued September 15 at 1:53PM CDT by NWS St Louis MO
Non-Weather Emergency Message. Not sent to IPAWS.
Effective: Mon September 15, 2025, 1:53 PM
Expires: Tue September 16, 2025, 2:00 PM
The St. Louis Clean Air Partnership has issued an air quality alert for the St. Louis metropolitan area until 8 PM CDT this evening. An Orange air quality forecast means that maximum ozone concentrations are expected to reach levels that pose a health risk. Adverse health effects increase as air quality deteriorates. Ground- level ozone is an air contaminant which can cause breathing difficulties for children, older adults, as well as persons with respiratory problems. Reducing outdoor physical activity is recommended. If it is a regularly scheduled work day you are urged to consider telecommuting, carpooling, or utilizing public transit. Avoid excessive idling and do not top off when refueling motor vehicles. The use of gasoline-powered lawn equipment should be reduced or postponed until late in the day. For more information visit the St. Louis Clean Air Partnership at http://cleanair-stlouis.com/ For current Air Quality Index (AQI) values visit https://www.airnow.gov/
Air Quality Alert issued September 15 at 8:04PM CDT by NWS St Louis MO
Non-Weather Emergency Message. Not sent to IPAWS.
Effective: Mon September 15, 2025, 8:04 PM
Expires: Tue September 16, 2025, 8:15 PM
The St. Louis Clean Air Partnership has issued an air quality alert for the St. Louis metropolitan area from 10 AM to 8 PM CDT Tuesday. An Orange air quality forecast means that maximum ozone concentrations are expected to reach levels that pose a health risk. Adverse health effects increase as air quality deteriorates. Ground- level ozone is an air contaminant which can cause breathing difficulties for children, older adults, as well as persons with respiratory problems. Reducing outdoor physical activity is recommended. If it is a regularly scheduled work day you are urged to consider telecommuting, carpooling, or utilizing public transit. Avoid excessive idling and do not top off when refueling motor vehicles. The use of gasoline-powered lawn equipment should be reduced or postponed until late in the day. For more information visit the St. Louis Clean Air Partnership at http://cleanair-stlouis.com/ For current Air Quality Index (AQI) values visit https://www.airnow.gov/
Air Quality Alert issued September 15 at 1:53PM CDT by NWS St Louis MO
Non-Weather Emergency Message. Not sent to IPAWS.
Effective: Mon September 15, 2025, 1:53 PM
Expires: Tue September 16, 2025, 2:00 PM
The St. Louis Clean Air Partnership has issued an air quality alert for the St. Louis metropolitan area until 8 PM CDT this evening. An Orange air quality forecast means that maximum ozone concentrations are expected to reach levels that pose a health risk. Adverse health effects increase as air quality deteriorates. Ground- level ozone is an air contaminant which can cause breathing difficulties for children, older adults, as well as persons with respiratory problems. Reducing outdoor physical activity is recommended. If it is a regularly scheduled work day you are urged to consider telecommuting, carpooling, or utilizing public transit. Avoid excessive idling and do not top off when refueling motor vehicles. The use of gasoline-powered lawn equipment should be reduced or postponed until late in the day. For more information visit the St. Louis Clean Air Partnership at http://cleanair-stlouis.com/ For current Air Quality Index (AQI) values visit https://www.airnow.gov/
Weather Forecast
Average Temperature: 83.5°F
Average Humidity: 52%
Wind: 8.9 mph
UV Index: 1.6
Air Quality
Nitrogen Dioxide: 24.43 μg/m3
Sulphur Dioxide: 13.45 μg/m3
Ozone: 104.04 μg/m3
Astronomical
Sun Transit: 12:56 AM
Sunset: 7:08 PM
Daylight: 12 hrs 23 mins
Moon Transit: 8:54 AM
Moonset: 4:40 PM
Moon Phase: Last Quarter
Moon Illumination: 23.8%
Best Times for Fishing or Hunting
Major Periods
8:24 AM - 10:54 AM8:48 PM - 11:18 PM
Minor Periods
4:10 PM - 5:40 PM12:30 AM - 2:00 AM
Action Rating: 2 out of 5
Weather Forecast
Average Temperature: 80.6°F
Average Humidity: 49%
Wind: 9.6 mph
UV Index: 1.6
Air Quality
Nitrogen Dioxide: 28.28 μg/m3
Sulphur Dioxide: 15.99 μg/m3
Ozone: 110.64 μg/m3
Astronomical
Sun Transit: 12:56 AM
Sunset: 7:06 PM
Daylight: 12 hrs 21 mins
Moon Transit: 9:48 AM
Moonset: 5:16 PM
Moon Phase: Waning Crescent
Moon Illumination: 14.9%
Best Times for Fishing or Hunting
Major Periods
12:00 AM - 12:00 AM9:18 AM - 11:48 AM
Minor Periods
4:46 PM - 6:16 PM1:41 AM - 3:11 AM
Action Rating: 2 out of 5
Weather Forecast
Average Temperature: 80.3°F
Average Humidity: 51%
Wind: 6 mph
UV Index: 1.5
Air Quality
Nitrogen Dioxide: 25.29 μg/m3
Sulphur Dioxide: 11.68 μg/m3
Ozone: 113.8 μg/m3
Astronomical
Sun Transit: 12:55 AM
Sunset: 7:05 PM
Daylight: 12 hrs 18 mins
Moon Transit: 10:39 AM
Moonset: 5:46 PM
Moon Phase: Waning Crescent
Moon Illumination: 7.8%
Best Times for Fishing or Hunting
Major Periods
12:00 AM - 12:00 AM10:09 AM - 12:39 AM
Minor Periods
5:16 PM - 6:46 PM2:50 AM - 4:20 AM
Action Rating: 3 out of 5
Weather Forecast
Average Temperature: 75.9°F
Average Humidity: 59%
Wind: 11.2 mph
UV Index: 0.4
Air Quality
Nitrogen Dioxide: 19.77 μg/m3
Sulphur Dioxide: 4.77 μg/m3
Ozone: 104.52 μg/m3
Astronomical
Sun Transit: 12:55 AM
Sunset: 7:03 PM
Daylight: 12 hrs 16 mins
Moon Transit: 11:25 AM
Moonset: 6:11 PM
Moon Phase: Waning Crescent
Moon Illumination: 2.8%
Best Times for Fishing or Hunting
Major Periods
12:00 AM - 12:00 AM10:55 AM - 1:25 PM
Minor Periods
5:41 PM - 7:11 PM3:58 AM - 5:28 AM
Action Rating: 3 out of 5
Weather Forecast
Average Temperature: 77.2°F
Average Humidity: 57%
Wind: 7.2 mph
UV Index: 0
Air Quality
Nitrogen Dioxide: 53.07 μg/m3
Sulphur Dioxide: 5.27 μg/m3
Ozone: 50.54 μg/m3
Astronomical
Sun Transit: 12:55 AM
Sunset: 7:02 PM
Daylight: 12 hrs 13 mins
Moon Transit: 12:08 AM
Moonset: 6:33 PM
Moon Phase: Waning Crescent
Moon Illumination: 0.3%
Best Times for Fishing or Hunting
Major Periods
12:00 AM - 12:00 AM11:38 AM - 2:08 PM
Minor Periods
6:03 PM - 7:33 PM5:03 AM - 6:33 AM
Action Rating: 3 out of 5