National Weather Service Forecast for: Saint Peters MO
Issued by: National Weather Service Saint Louis, MO
Updated: 1:21 am CDT Jun 30, 2026
 
Overnight

Overnight: Mostly clear, with a low around 76. Southwest wind 6 to 8 mph.
Mostly Clear

Tuesday

Tuesday: Sunny and hot, with a high near 97. Heat index values as high as 106. Southwest wind 6 to 8 mph.
Hot

Tuesday
Night
Tuesday Night: Clear, with a low around 77. South wind 5 to 7 mph.
Clear

Wednesday

Wednesday: Sunny, with a high near 96. Heat index values as high as 105. Southwest wind 5 to 7 mph.
Sunny

Wednesday
Night
Wednesday Night: Clear, with a low around 78. South wind 5 to 7 mph.
Clear

Thursday

Thursday: A 20 percent chance of showers and thunderstorms after 1pm.  Sunny, with a high near 96.
Sunny then
Slight Chance
T-storms
Thursday
Night
Thursday Night: A 20 percent chance of showers and thunderstorms before 1am.  Partly cloudy, with a low around 77.
Slight Chance
T-storms
Friday

Friday: A 20 percent chance of showers and thunderstorms after 1pm.  Sunny, with a high near 95.
Sunny then
Slight Chance
T-storms
Friday
Night
Friday Night: A 20 percent chance of showers and thunderstorms.  Partly cloudy, with a low around 76.
Slight Chance
T-storms
Lo 76 °F Hi 97 °F Lo 77 °F Hi 96 °F Lo 78 °F Hi 96 °F Lo 77 °F Hi 95 °F Lo 76 °F

Extreme Heat Warning
 

Overnight
 
Mostly clear, with a low around 76. Southwest wind 6 to 8 mph.
Tuesday
 
Sunny and hot, with a high near 97. Heat index values as high as 106. Southwest wind 6 to 8 mph.
Tuesday Night
 
Clear, with a low around 77. South wind 5 to 7 mph.
Wednesday
 
Sunny, with a high near 96. Heat index values as high as 105. Southwest wind 5 to 7 mph.
Wednesday Night
 
Clear, with a low around 78. South wind 5 to 7 mph.
Thursday
 
A 20 percent chance of showers and thunderstorms after 1pm. Sunny, with a high near 96.
Thursday Night
 
A 20 percent chance of showers and thunderstorms before 1am. Partly cloudy, with a low around 77.
Friday
 
A 20 percent chance of showers and thunderstorms after 1pm. Sunny, with a high near 95.
Friday Night
 
A 20 percent chance of showers and thunderstorms. Partly cloudy, with a low around 76.
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 75.
Sunday
 
A 30 percent chance of showers and thunderstorms. Mostly sunny, with a high near 92.
Sunday Night
 
A 30 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 Saint Peters MO.