National Weather Service Forecast for: Ballwin MO
Issued by: National Weather Service Saint Louis, MO
Updated: 11:30 pm CDT Jun 18, 2026
 
Tonight

Tonight: Patchy fog after 4am. Otherwise, partly cloudy, with a low around 61. Calm wind.
Patchy Fog

 Juneteenth

Juneteenth: Patchy fog before 7am. Otherwise, sunny, with a high near 83. Light northwest wind.
Patchy Fog
then Mostly
Sunny
 Friday
Night
Friday Night: Mostly cloudy, with a low around 64. Calm wind.
Mostly Cloudy

 Saturday

Saturday: Mostly sunny, with a high near 86. Light southwest wind.
Mostly Sunny

 Saturday
Night
Saturday Night: A chance of showers between 1am and 4am, then a chance of showers and thunderstorms after 4am. Partly cloudy, with a low around 67. Light southeast wind. Chance of precipitation is 30%.
Mostly Clear
then Chance
Showers
 Sunday

Sunday: Showers and possibly a thunderstorm. High near 83. Chance of precipitation is 80%.
Showers
Likely then
T-storms
 Sunday
Night
Sunday Night: Showers and possibly a thunderstorm before 1am, then a chance of showers. Low around 65. Chance of precipitation is 90%.
Showers

 Monday

Monday: A 20 percent chance of showers and thunderstorms before 1pm. Mostly cloudy, with a high near 79.
Slight Chance
T-storms
 Monday
Night
Monday Night: Partly cloudy, with a low around 61.
Partly Cloudy
Lo 61 °F Hi 83 °F Lo 64 °F Hi 86 °F Lo 67 °F Hi 83 °F Lo 65 °F Hi 79 °F Lo 61 °F

 

Tonight
 
 Patchy fog after 4am. Otherwise, partly cloudy, with a low around 61. Calm wind.
Juneteenth
 
 Patchy fog before 7am. Otherwise, sunny, with a high near 83. Light northwest wind.
Friday Night
 
 Mostly cloudy, with a low around 64. Calm wind.
Saturday
 
 Mostly sunny, with a high near 86. Light southwest wind.
Saturday Night
 
 A chance of showers between 1am and 4am, then a chance of showers and thunderstorms after 4am. Partly cloudy, with a low around 67. Light southeast wind. Chance of precipitation is 30%.
Sunday
 
 Showers and possibly a thunderstorm. High near 83. Chance of precipitation is 80%.
Sunday Night
 
 Showers and possibly a thunderstorm before 1am, then a chance of showers. Low around 65. Chance of precipitation is 90%.
Monday
 
 A 20 percent chance of showers and thunderstorms before 1pm. Mostly cloudy, with a high near 79.
Monday Night
 
 Partly cloudy, with a low around 61.
Tuesday
 
 Mostly sunny, with a high near 81.
Tuesday Night
 
 A 20 percent chance of showers. Partly cloudy, with a low around 63.
Wednesday
 
 Mostly sunny, with a high near 83.
Wednesday Night
 
 Mostly clear, with a low around 63.
Thursday
 
 A 20 percent chance of showers and thunderstorms. Mostly sunny, with a high near 83.

 

Forecast from NOAA-NWS for Ballwin MO.