Weather for St Charles, Missouri
Current Weather
Five Day Weather Forecast
Tue
H: 99°F
L: 78°F
Wed
H: 87°F
L: 70°F
Thu
H: 90°F
L: 68°F
Fri
H: 89°F
L: 67°F
Sat
H: 75°F
L: 65°F
Air Quality
Nitrogen Dioxide: 5.7 μg/m3
Sulphur Dioxide: 1.7 μg/m3
Ozone: 91 μg/m3
Astronomical
Sun Transit: 1:08 PM
Sunset: 8:17 PM
Daylight: 14 hrs 17 mins
Moon Transit: 12:05 AM
Moonset: 4:47 AM
Moon Phase: Full
Moon Illumination: 99.7%
Best Times for Fishing or Hunting
Major Periods
12:00 AM - 12:00 AM11:56 AM - 2:26 PM
Minor Periods
7:35 PM - 9:05 PM4:17 AM - 5:47 AM
Action Rating: 4 out of 5
Extreme Heat Warning issued July 27 at 9:10PM CDT until July 28 at 7:00PM CDT by NWS St Louis MO
Effective: Mon July 27, 2026, 9:10 PM
Expires: Tue July 28, 2026, 12:15 PM
* WHAT...Dangerously hot conditions with heat index values up to 106. * WHERE...In Illinois, Monroe IL and Saint Clair IL Counties. In Missouri, Jefferson MO County. * WHEN...Until 7 PM CDT Tuesday. * IMPACTS...Heat related illnesses increase significantly during extreme heat and high humidity events.
Drink plenty of fluids, stay in an air-conditioned room, stay out of the sun, and check up on relatives and neighbors. Young children and pets should never be left unattended in vehicles under any circumstances. Take extra precautions if you work or spend time outside. When possible reschedule strenuous activities to early morning or evening. Know the signs and symptoms of heat exhaustion and heat stroke. Wear lightweight and loose fitting clothing when possible. To reduce risk during outdoor work, the Occupational Safety and Health Administration recommends scheduling frequent rest breaks in shaded or air conditioned environments. Anyone overcome by heat should be moved to a cool and shaded location. Heat stroke is an emergency! Call 9 1 1.
Weather Forecast
Air Quality
Nitrogen Dioxide: 6.51 μg/m3
Sulphur Dioxide: 1.52 μg/m3
Ozone: 90.83 μg/m3
Astronomical
Sun Transit: 1:08 PM
Sunset: 8:17 PM
Daylight: 14 hrs 17 mins
Moon Transit: 12:05 AM
Moonset: 4:47 AM
Moon Phase: Full
Moon Illumination: 99.7%
Best Times for Fishing or Hunting
Major Periods
12:00 AM - 12:00 AM11:56 AM - 2:26 PM
Minor Periods
7:35 PM - 9:05 PM4:17 AM - 5:47 AM
Action Rating: 4 out of 5
Weather Forecast
Air Quality
Nitrogen Dioxide: 9.51 μg/m3
Sulphur Dioxide: 2.73 μg/m3
Ozone: 84.21 μg/m3
Astronomical
Sun Transit: 1:08 PM
Sunset: 8:16 PM
Daylight: 14 hrs 15 mins
Moon Transit: 12:54 AM
Moonset: 5:50 AM
Moon Phase: Full
Moon Illumination: 99.7%
Best Times for Fishing or Hunting
Major Periods
12:24 AM - 2:54 AM12:43 AM - 3:13 PM
Minor Periods
8:05 PM - 9:35 PM5:20 AM - 6:50 AM
Action Rating: 4 out of 5
Weather Forecast
Air Quality
Nitrogen Dioxide: 12.85 μg/m3
Sulphur Dioxide: 3.12 μg/m3
Ozone: 89.13 μg/m3
Astronomical
Sun Transit: 1:08 PM
Sunset: 8:15 PM
Daylight: 14 hrs 13 mins
Moon Transit: 1:40 AM
Moonset: 6:54 AM
Moon Phase: Full
Moon Illumination: 97.1%
Best Times for Fishing or Hunting
Major Periods
1:10 AM - 3:40 AM1:30 PM - 4:00 PM
Minor Periods
8:32 PM - 10:02 PM6:24 AM - 7:54 AM
Action Rating: 5 out of 5
Weather Forecast
Air Quality
Nitrogen Dioxide: 9.08 μg/m3
Sulphur Dioxide: 3.65 μg/m3
Ozone: 99.63 μg/m3
Astronomical
Sun Transit: 1:08 PM
Sunset: 8:14 PM
Daylight: 14 hrs 11 mins
Moon Transit: 2:25 AM
Moonset: 7:57 AM
Moon Phase: Full
Moon Illumination: 92.0%
Best Times for Fishing or Hunting
Major Periods
1:55 AM - 4:25 AM2:12 PM - 4:42 PM
Minor Periods
8:55 PM - 10:25 PM7:27 AM - 8:57 AM
Action Rating: 3 out of 5
Weather Forecast
Air Quality
Nitrogen Dioxide: 6.31 μg/m3
Sulphur Dioxide: 1.71 μg/m3
Ozone: 95.75 μg/m3
Astronomical
Sun Transit: 1:08 PM
Sunset: 8:13 PM
Daylight: 14 hrs 10 mins
Moon Transit: 3:08 AM
Moonset: 9:01 AM
Moon Phase: Waning Gibbous
Moon Illumination: 84.9%
Best Times for Fishing or Hunting
Major Periods
2:38 AM - 5:08 AM2:55 PM - 5:25 PM
Minor Periods
9:18 PM - 10:48 PM8:31 AM - 10:01 AM
Action Rating: 2 out of 5