National Weather Service Forecast for: Saint Peters MO
Issued by: National Weather Service Saint Louis, MO
Updated: 3:26 am CDT Aug 20, 2026
 
Today

Today: Partly sunny, with a high near 83. North wind 3 to 6 mph.
Partly Sunny

 Tonight

Tonight: Patchy fog after 5am. Otherwise, mostly clear, with a low around 66. Northeast wind around 5 mph becoming calm in the evening.
Mostly Clear
then Patchy
Fog
 Friday

Friday: Patchy fog before 8am. Otherwise, sunny, with a high near 87. Calm wind.
Patchy Fog
then Sunny

 Friday
Night
Friday Night: Partly cloudy, with a low around 70. Light southwest wind.
Partly Cloudy

 Saturday

Saturday: Sunny, with a high near 85. Northwest wind 3 to 7 mph.
Sunny

 Saturday
Night
Saturday Night: Mostly clear, with a low around 66.
Mostly Clear

 Sunday

Sunday: Mostly sunny, with a high near 82.
Mostly Sunny

 Sunday
Night
Sunday Night: Mostly cloudy, with a low around 65.
Mostly Cloudy

 Monday

Monday: A slight chance of showers, with thunderstorms also possible after 1pm. Partly sunny, with a high near 82. Chance of precipitation is 20%.
Slight Chance
Showers then
Slight Chance
T-storms
Hi 83 °F Lo 66 °F Hi 87 °F Lo 70 °F Hi 85 °F Lo 66 °F Hi 82 °F Lo 65 °F Hi 82 °F

 

Today
 
 Partly sunny, with a high near 83. North wind 3 to 6 mph.
Tonight
 
 Patchy fog after 5am. Otherwise, mostly clear, with a low around 66. Northeast wind around 5 mph becoming calm in the evening.
Friday
 
 Patchy fog before 8am. Otherwise, sunny, with a high near 87. Calm wind.
Friday Night
 
 Partly cloudy, with a low around 70. Light southwest wind.
Saturday
 
 Sunny, with a high near 85. Northwest wind 3 to 7 mph.
Saturday Night
 
 Mostly clear, with a low around 66.
Sunday
 
 Mostly sunny, with a high near 82.
Sunday Night
 
 Mostly cloudy, with a low around 65.
Monday
 
 A slight chance of showers, with thunderstorms also possible after 1pm. Partly sunny, with a high near 82. Chance of precipitation is 20%.
Monday Night
 
 Partly cloudy, with a low around 66.
Tuesday
 
 Mostly sunny, with a high near 86.
Tuesday Night
 
 Partly cloudy, with a low around 69.
Wednesday
 
 A 20 percent chance of showers and thunderstorms. Mostly sunny, with a high near 87.

 

Forecast from NOAA-NWS for Saint Peters MO.