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National Weather Service Forecast for: St. Charles County
Issued by: NWS National Weather Service Saint Louis, MO
Updated: 124 AM CDT Fri Jul 11 2025
St. Charles , MO
 
Rest
Of Tonight

Mostly Clear
Mostly Clear
Friday


Thunder storm
Thunder storm
Friday
Night

Thunder storm
Thunder storm
Saturday


Thunder storm
Thunder storm
Saturday
Night

Thunder storm
Thunder storm
Sunday


Thunder storm
Thunder storm
Sunday
Night

Thunder storm
Thunder storm
Monday


Sunny
Sunny
Monday
Night

Mostly Cloudy
Mostly Cloudy
Lo ≈75°F Hi ≈95°F Lo ≈75°F Hi ≈95°F Lo ≈75°F Hi ≈85°F Lo ≈70°F Hi ≈90°F Lo ≈75°F

 

Rest Of Tonight
 
Mostly clear. Lows in the lower 70s. South winds around 5 mph.
Friday
 
Mostly sunny. Isolated showers and thunderstorms in the afternoon. Highs in the mid 90s. South winds 5 to 10 mph. Chance of rain 20 percent. Heat index values up to 104.
Friday Night
 
Partly cloudy with a chance of showers and thunderstorms. Lows in the lower 70s. South winds 5 to 10 mph. Chance of rain 50 percent. Heat index values up to 100 early in the evening.
Saturday
 
Mostly sunny. A slight chance of showers and thunderstorms in the morning, then a chance of showers and thunderstorms in the afternoon. Humid with highs in the lower 90s. Southwest winds 5 to 10 mph. Chance of rain 50 percent.
Saturday Night
 
Mostly cloudy. A chance of showers and thunderstorms, mainly in the evening. Lows in the lower 70s. Southwest winds 5 to 10 mph. Chance of rain 50 percent.
Sunday
 
Mostly cloudy with a slight chance of showers and thunderstorms in the morning, then partly sunny with a chance of showers and thunderstorms in the afternoon. Highs in the upper 80s. Chance of rain 50 percent.
Sunday Night
 
Mostly cloudy with a slight chance of showers and thunderstorms in the evening, then partly cloudy after midnight. Lows around 70. Chance of rain 20 percent.
Monday
 
Sunny. Highs around 90.
Monday Night
 
Partly cloudy in the evening, then becoming mostly cloudy. Lows in the lower 70s.
Tuesday
 
Mostly cloudy. A slight chance of showers and thunderstorms. Highs in the lower 90s.
Tuesday Night
 
Mostly cloudy. A slight chance of showers and thunderstorms. Lows in the mid 70s.
Wednesday
 
Mostly sunny. A slight chance of showers and thunderstorms in the morning, then a chance of showers and thunderstorms in the afternoon. Highs in the lower 90s. Chance of rain 50 percent. Heat index values up to 100.
Wednesday Night
 
Mostly cloudy with a chance of showers and thunderstorms. Lows around 70. Chance of rain 50 percent.
Thursday
 
Mostly cloudy with a slight chance of showers in the morning, then partly sunny with a chance of showers and thunderstorms in the afternoon. Highs in the mid 80s. Chance of rain 40 percent.
Zone Forecast
 
St. Charles County

 

Forecast from NOAA-NWS for St. Charles County. (Zone forecast)