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

82°F

28°C

Humidity 63%
Wind Speed S 6 mph
Barometer 29.89 in (1011.6 mb)
Dewpoint 68°F (20°C)
Visibility 10.00 mi
Heat Index85°F (29°C)
Last update 13 Oct 7:53 pm CDT
Extended Forecast for

Mascoutah IL

  • Tonight

    Tonight: A chance of showers and thunderstorms, then showers likely and possibly a thunderstorm after 5am. Increasing clouds, with a low around 72. South wind 5 to 8 mph. Chance of precipitation is 60%.

    Low: 72 °F

    Clear then
    Showers
    Likely

  • Wednesday

    Wednesday: Showers and possibly a thunderstorm, mainly before 1pm, then a chance of showers and thunderstorms after 1pm. High near 78. Light and variable wind becoming north around 6 mph in the afternoon. Chance of precipitation is 90%.

    High: 78 °F

    Showers then
    Showers
    Likely

  • Wednesday Night

    Wednesday Night: A chance of showers and thunderstorms, then showers likely and possibly a thunderstorm after 3am. Mostly cloudy, with a low around 67. East wind 5 to 7 mph. Chance of precipitation is 70%.

    Low: 67 °F

    Slight Chance
    T-storms then
    Showers
    Likely

  • Thursday

    Thursday: Showers and possibly a thunderstorm. High near 84. Light and variable wind becoming southwest 5 to 10 mph in the morning. Chance of precipitation is 90%.

    High: 84 °F

    Showers

  • Thursday Night

    Thursday Night: A chance of showers and thunderstorms before 1am, then a slight chance of showers. Mostly cloudy, with a low around 50. West wind 7 to 12 mph becoming northwest 13 to 18 mph after midnight. Winds could gust as high as 28 mph. Chance of precipitation is 50%.

    Low: 50 °F

    Chance
    T-storms then
    Chance
    Showers

  • Friday

    Friday: Mostly sunny, with a high near 61. Breezy.

    High: 61 °F

    Mostly Sunny
    and Breezy

  • Friday Night

    Friday Night: Mostly clear, with a low around 37.

    Low: 37 °F

    Mostly Clear

  • Saturday

    Saturday: Sunny, with a high near 63.

    High: 63 °F

    Sunny

  • Saturday Night

    Saturday Night: Clear, with a low around 37.

    Low: 37 °F

    Clear

Detailed Forecast

Tonight
A chance of showers and thunderstorms, then showers likely and possibly a thunderstorm after 5am. Increasing clouds, with a low around 72. South wind 5 to 8 mph. Chance of precipitation is 60%.
Wednesday
Showers and possibly a thunderstorm, mainly before 1pm, then a chance of showers and thunderstorms after 1pm. High near 78. Light and variable wind becoming north around 6 mph in the afternoon. Chance of precipitation is 90%.
Wednesday Night
A chance of showers and thunderstorms, then showers likely and possibly a thunderstorm after 3am. Mostly cloudy, with a low around 67. East wind 5 to 7 mph. Chance of precipitation is 70%.
Thursday
Showers and possibly a thunderstorm. High near 84. Light and variable wind becoming southwest 5 to 10 mph in the morning. Chance of precipitation is 90%.
Thursday Night
A chance of showers and thunderstorms before 1am, then a slight chance of showers. Mostly cloudy, with a low around 50. West wind 7 to 12 mph becoming northwest 13 to 18 mph after midnight. Winds could gust as high as 28 mph. Chance of precipitation is 50%.
Friday
Mostly sunny, with a high near 61. Breezy.
Friday Night
Mostly clear, with a low around 37.
Saturday
Sunny, with a high near 63.
Saturday Night
Clear, with a low around 37.
Sunday
Sunny, with a high near 70.
Sunday Night
Partly cloudy, with a low around 45.
Monday
Mostly sunny, with a high near 74.
Monday Night
Partly cloudy, with a low around 49.
Tuesday
Mostly sunny, with a high near 78.
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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:
6:01 pm CDT Oct 13, 2026
Forecast Valid:
8pm CDT Oct 13, 2026-6pm CDT Oct 20, 2026
 
Forecast Discussion
 
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Additional Resources

Radar & Satellite Image

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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