National Oceanic and Atmospheric Administration National Weather Service United States Department of Commerce
Current conditions at

St. Louis Downtown Airport (KCPS)

Lat: 38.56°NLon: 90.15°WElev: 410ft.

Fair

72°F

22°C

Humidity 84%
Wind Speed Calm
Barometer 30.00 in (1015.3 mb)
Dewpoint 67°F (19°C)
Visibility 10.00 mi
Last update 29 Jul 10:53 pm CDT
Extended Forecast for

Mascoutah IL

  • Tonight

    Tonight: Clear, with a low around 65. Light northeast wind.

    Low: 65 °F

    Clear

  • Thursday

    Thursday: Mostly sunny, with a high near 86. Calm wind becoming east around 6 mph in the morning.

    High: 86 °F

    Mostly Sunny

  • Thursday Night

    Thursday Night: Partly cloudy, with a low around 67. East wind around 5 mph becoming calm in the evening.

    Low: 67 °F

    Partly Cloudy

  • Friday

    Friday: A chance of showers, then showers likely and possibly a thunderstorm after 1pm. Partly sunny, with a high near 85. Light south wind increasing to 6 to 11 mph in the morning. Chance of precipitation is 60%.

    High: 85 °F

    Chance
    Showers then
    Showers
    Likely

  • Friday Night

    Friday Night: Showers and possibly a thunderstorm before 4am, then showers likely. Low around 68. South wind 6 to 11 mph becoming southwest after midnight. Chance of precipitation is 90%.

    Low: 68 °F

    Showers

  • Saturday

    Saturday: A chance of showers, with thunderstorms also possible after 1pm. Mostly cloudy, with a high near 79. Chance of precipitation is 40%.

    High: 79 °F

    Chance
    Showers then
    Chance
    T-storms

  • Saturday Night

    Saturday Night: A 20 percent chance of showers and thunderstorms before 1am. Partly cloudy, with a low around 66.

    Low: 66 °F

    Slight Chance
    T-storms

  • Sunday

    Sunday: A 20 percent chance of showers after 1pm. Mostly sunny, with a high near 82.

    High: 82 °F

    Mostly Sunny
    then Slight
    Chance
    Showers

  • Sunday Night

    Sunday Night: Mostly clear, with a low around 65.

    Low: 65 °F

    Mostly Clear

Detailed Forecast

Tonight
Clear, with a low around 65. Light northeast wind.
Thursday
Mostly sunny, with a high near 86. Calm wind becoming east around 6 mph in the morning.
Thursday Night
Partly cloudy, with a low around 67. East wind around 5 mph becoming calm in the evening.
Friday
A chance of showers, then showers likely and possibly a thunderstorm after 1pm. Partly sunny, with a high near 85. Light south wind increasing to 6 to 11 mph in the morning. Chance of precipitation is 60%.
Friday Night
Showers and possibly a thunderstorm before 4am, then showers likely. Low around 68. South wind 6 to 11 mph becoming southwest after midnight. Chance of precipitation is 90%.
Saturday
A chance of showers, with thunderstorms also possible after 1pm. Mostly cloudy, with a high near 79. Chance of precipitation is 40%.
Saturday Night
A 20 percent chance of showers and thunderstorms before 1am. Partly cloudy, with a low around 66.
Sunday
A 20 percent chance of showers after 1pm. Mostly sunny, with a high near 82.
Sunday Night
Mostly clear, with a low around 65.
Monday
A 20 percent chance of showers and thunderstorms after 1pm. Sunny, with a high near 84.
Monday Night
Mostly clear, with a low around 67.
Tuesday
A 20 percent chance of showers and thunderstorms. Mostly sunny, with a high near 87.
Tuesday Night
Partly cloudy, with a low around 69.
Wednesday
A 20 percent chance of showers and thunderstorms. Mostly sunny, with a high near 89.
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Forecast Area
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ABOUT THIS FORECAST

 
Point Forecast:
Mascoutah IL
 38.52°N 89.81°W (Elev. 423 ft)
Last Update:
10:11 pm CDT Jul 29, 2026
Forecast Valid:
11pm CDT Jul 29, 2026-6pm CDT Aug 5, 2026
 
Forecast Discussion
 
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Additional Resources

Radar & Satellite Image

Link to Local Radar Data Link to Satellite Data

Hourly Weather Forecast

National Digital Forecast Database

National Digital Forecast Database Maximum Temperature Forecast

High Temperature

National Digital Forecast Database Weather Element Forecast

Chance of Precipitation