National Weather Service Forecast for: Ballwin MO
Issued by: National Weather Service Saint Louis, MO
Updated: 2:21 am CDT Jun 30, 2026
 
Today

Today: Sunny and hot, with a high near 97. Heat index values as high as 106. Southwest wind 5 to 7 mph.
Hot

 Tonight

Tonight: Clear, with a low around 77. South wind around 6 mph.
Clear

 Wednesday

Wednesday: Sunny and hot, with a high near 97. Heat index values as high as 105. Southwest wind around 6 mph.
Hot

 Wednesday
Night
Wednesday Night: Clear, with a low around 77. South wind 3 to 6 mph.
Clear

 Thursday

Thursday: A 20 percent chance of showers and thunderstorms after 1pm. Sunny, with a high near 96. Southwest wind 3 to 5 mph.
Sunny then
Slight Chance
T-storms
 Thursday
Night
Thursday Night: A slight chance of showers and thunderstorms before 10pm, then a slight chance of showers between 10pm and 1am. Partly cloudy, with a low around 76. Chance of precipitation is 20%.
Slight Chance
T-storms then
Slight Chance
Showers
 Friday

Friday: A 20 percent chance of showers and thunderstorms after 1pm. Sunny, with a high near 96.
Sunny then
Slight Chance
T-storms
 Friday
Night
Friday Night: A 20 percent chance of showers and thunderstorms. Partly cloudy, with a low around 75.
Slight Chance
T-storms

 Independence
Day
Independence Day: A 30 percent chance of showers and thunderstorms, mainly after 1pm. Mostly sunny, with a high near 95.
Chance
T-storms
Hi 97 °F Lo 77 °F Hi 97 °F Lo 77 °F Hi 96 °F Lo 76 °F Hi 96 °F Lo 75 °F Hi 95 °F

Extreme Heat Warning
 

Today
 
 Sunny and hot, with a high near 97. Heat index values as high as 106. Southwest wind 5 to 7 mph.
Tonight
 
 Clear, with a low around 77. South wind around 6 mph.
Wednesday
 
 Sunny and hot, with a high near 97. Heat index values as high as 105. Southwest wind around 6 mph.
Wednesday Night
 
 Clear, with a low around 77. South wind 3 to 6 mph.
Thursday
 
 A 20 percent chance of showers and thunderstorms after 1pm. Sunny, with a high near 96. Southwest wind 3 to 5 mph.
Thursday Night
 
 A slight chance of showers and thunderstorms before 10pm, then a slight chance of showers between 10pm and 1am. Partly cloudy, with a low around 76. Chance of precipitation is 20%.
Friday
 
 A 20 percent chance of showers and thunderstorms after 1pm. Sunny, with a high near 96.
Friday Night
 
 A 20 percent chance of showers and thunderstorms. Partly cloudy, with a low around 75.
Independence Day
 
 A 30 percent chance of showers and thunderstorms, mainly after 1pm. Mostly sunny, with a high near 95.
Saturday Night
 
 A 20 percent chance of showers and thunderstorms. Partly cloudy, with a low around 74.
Sunday
 
 A 40 percent chance of showers and thunderstorms. Mostly sunny, with a high near 93.
Sunday Night
 
 A 40 percent chance of showers and thunderstorms. Partly cloudy, with a low around 73.
Monday
 
 A 30 percent chance of showers and thunderstorms. Mostly sunny, with a high near 90.

 

Forecast from NOAA-NWS for Ballwin MO.