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.

N/A

Humidity NA
Wind Speed NA
Barometer NA
Dewpoint N/A
Visibility NA
Last update *** Not a current observation ***
Extended Forecast for

Mascoutah IL

  • Tonight

    Tonight: Clear, with a low around 44. South wind around 7 mph.

    Low: 44 °F

    Clear

  • Monday

    Monday: Sunny, with a high near 75. South wind 6 to 11 mph increasing to 12 to 17 mph in the afternoon. Winds could gust as high as 28 mph.

    High: 75 °F

    Sunny

  • Monday Night

    Monday Night: Mostly clear, with a low around 61. South wind 8 to 13 mph, with gusts as high as 21 mph.

    Low: 61 °F

    Mostly Clear

  • Tuesday

    Tuesday: A 30 percent chance of showers and thunderstorms after 1pm. Increasing clouds, with a high near 79. South wind 7 to 16 mph, with gusts as high as 23 mph.

    High: 79 °F

    Mostly Sunny
    then Chance
    T-storms

  • Tuesday Night

    Tuesday Night: Showers and possibly a thunderstorm. Low around 56. Southwest wind around 16 mph, with gusts as high as 26 mph. Chance of precipitation is 90%.

    Low: 56 °F

    Showers

  • Wednesday

    Wednesday: Showers and possibly a thunderstorm before 1pm, then showers likely. Temperature rising to near 66 by 8am, then falling to around 51 during the remainder of the day. Breezy. Chance of precipitation is 100%.

    High: 66 °F⇓

    Showers and
    Breezy

  • Wednesday Night

    Wednesday Night: A 20 percent chance of showers before 1am. Mostly cloudy, with a low around 37. Breezy.

    Low: 37 °F

    Slight Chance
    Showers and
    Breezy

  • Thursday

    Thursday: Sunny, with a high near 53.

    High: 53 °F

    Sunny

  • Thursday Night

    Thursday Night: Partly cloudy, with a low around 43.

    Low: 43 °F

    Partly Cloudy

Detailed Forecast

Tonight
Clear, with a low around 44. South wind around 7 mph.
Monday
Sunny, with a high near 75. South wind 6 to 11 mph increasing to 12 to 17 mph in the afternoon. Winds could gust as high as 28 mph.
Monday Night
Mostly clear, with a low around 61. South wind 8 to 13 mph, with gusts as high as 21 mph.
Tuesday
A 30 percent chance of showers and thunderstorms after 1pm. Increasing clouds, with a high near 79. South wind 7 to 16 mph, with gusts as high as 23 mph.
Tuesday Night
Showers and possibly a thunderstorm. Low around 56. Southwest wind around 16 mph, with gusts as high as 26 mph. Chance of precipitation is 90%.
Wednesday
Showers and possibly a thunderstorm before 1pm, then showers likely. Temperature rising to near 66 by 8am, then falling to around 51 during the remainder of the day. Breezy. Chance of precipitation is 100%.
Wednesday Night
A 20 percent chance of showers before 1am. Mostly cloudy, with a low around 37. Breezy.
Thursday
Sunny, with a high near 53.
Thursday Night
Partly cloudy, with a low around 43.
Friday
Mostly sunny, with a high near 64.
Friday Night
Mostly cloudy, with a low around 38.
Saturday
Partly sunny, with a high near 58.
Saturday Night
A 20 percent chance of showers. Mostly cloudy, with a low around 43.
Sunday
A 50 percent chance of showers. Mostly cloudy, with a high near 64.
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Forecast Area
Tiles ©ESRI

ABOUT THIS FORECAST

 
Point Forecast:
Mascoutah IL
 38.5°N 89.78°W (Elev. 440 ft)
Last Update:
6:16 pm CDT Mar 8, 2026
Forecast Valid:
9pm CDT Mar 8, 2026-6pm CDT Mar 15, 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