| National Weather Service Forecast for:
St. Charles County Issued by: NWS National Weather Service Saint Louis, MO |
||||||||||||||||||
| Updated: 408 PM CDT Thu Sep 18 2025 | ||||||||||||||||||
| St. Charles , MO | ||||||||||||||||||
|
| Tonight |
Partly cloudy this evening, then becoming mostly cloudy. Isolated showers and thunderstorms. Lows in the mid 60s. Northeast winds around 5 mph, becoming north after midnight. Chance of rain 20 percent. |
| Friday |
Mostly cloudy in the morning, then becoming partly sunny. Isolated showers. Isolated thunderstorms in the afternoon. Highs in the mid 80s. West winds around 5 mph. Chance of rain 20 percent. |
| Friday Night |
Partly cloudy. A chance of showers and thunderstorms, mainly in the evening. Lows in the mid 60s. Southwest winds around 5 mph in the evening, becoming light and variable. Chance of rain 40 percent. |
| Saturday |
Mostly sunny. A slight chance of showers and thunderstorms in the afternoon. Highs in the upper 80s. Southwest winds around 5 mph. Chance of rain 20 percent. |
| Saturday Night |
Mostly cloudy. A slight chance of showers and thunderstorms in the evening, then a chance of showers and thunderstorms after midnight. Lows in the mid 60s. South winds around 5 mph. Chance of rain 40 percent. |
| Sunday |
Mostly cloudy with a chance of showers with a slight chance of thunderstorms in the morning, then partly sunny with showers likely with a chance of thunderstorms in the afternoon. Highs in the mid 80s. Chance of rain 60 percent. |
| Sunday Night |
A chance of thunderstorms. A chance of showers in the evening, then showers likely after midnight. Lows in the mid 60s. Chance of rain 70 percent. |
| Monday |
Mostly cloudy. A chance of showers and thunderstorms. Highs in the mid 80s. |
| Monday Night |
Mostly cloudy. A chance of showers and thunderstorms. Lows in the mid 60s. |
| Tuesday |
Mostly cloudy with a chance of thunderstorms. A chance of showers. Highs around 80. Chance of rain 50 percent. |
| Tuesday Night |
Mostly cloudy with a chance of showers with a slight chance of thunderstorms. Lows in the lower 60s. Chance of rain 50 percent. |
| Wednesday |
Mostly cloudy. A 40 percent chance of showers. Highs in the upper 70s. |
| Wednesday Night |
Mostly cloudy. A 40 percent chance of showers. Lows around 60. |
| Thursday |
Mostly sunny. A slight chance of showers in the morning, then a chance of showers in the afternoon. Highs in the upper 70s. Chance of rain 40 percent. |
| Zone Forecast |
St. Charles County |
Forecast from NOAA-NWS for St. Charles County. (Zone forecast)