Home

National Weather Service Forecast for: St. Charles County
Issued by: NWS National Weather Service Saint Louis, MO
Updated: 539 PM CDT Fri Jul 18 2025
St. Charles , MO
 
Tonight


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


Thunder storm
Thunder storm		 Monday
Night

Thunder storm
Thunder storm		 Tuesday


Thunder storm
Thunder storm		 Tuesday
Night

Hot
Hot
Lo ≈75°F Hi ≈95°F Lo ≈75°F Hi ≈95°F Lo ≈75°F Hi ≈95°F Lo ≈75°F Hi ≈95°F Lo ≈75°F

 

Tonight
 
 Mostly cloudy with scattered showers and thunderstorms. Lows in the mid 70s. Southeast winds around 5 mph. Chance of rain 30 percent.
Saturday
 
 Mostly sunny with a chance of showers and thunderstorms. Humid with highs in the lower 90s. Southwest winds 5 to 10 mph. Chance of rain 50 percent. Heat index values up to 106 in the afternoon.
Saturday Night
 
 A slight chance of thunderstorms in the evening. Mostly clear with a slight chance of showers. Humid with lows in the mid 70s. Southwest winds around 5 mph. Chance of rain 20 percent. Heat index values up to 104 early in the evening.
Sunday
 
 Mostly sunny with a slight chance of showers and thunderstorms. Hot with highs in the mid 90s. Southwest winds around 5 mph. Chance of rain 20 percent. Heat index values up to 109.
Sunday Night
 
 Mostly clear with a chance of showers and thunderstorms in the evening, then partly cloudy with a slight chance of showers and thunderstorms after midnight. Humid with lows in the mid 70s. South winds around 5 mph. Chance of rain 40 percent. Heat index values up to 107 early in the evening.
Monday
 
 Partly cloudy. A slight chance of showers and thunderstorms. Highs in the mid 90s.
Monday Night
 
 Partly cloudy. A slight chance of showers and thunderstorms. Lows in the mid 70s.
Tuesday
 
 Sunny. A slight chance of showers and thunderstorms in the morning. Hot with highs in the mid 90s. Chance of rain 20 percent. Heat index values up to 110.
Tuesday Night
 
 Mostly clear. Hot. Lows in the upper 70s.
Wednesday
 
 Mostly clear. Hot. Highs in the upper 90s.
Wednesday Night
 
 Mostly clear. Hot. Lows in the upper 70s.
Thursday
 
 Mostly clear. Hot. Highs in the upper 90s.
Thursday Night
 
 Mostly clear. Hot. Lows in the upper 70s.
Friday
 
 Mostly clear. Hot. Highs in the upper 90s.
Zone Forecast
 
 St. Charles County

 

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