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

66°F

19°C

Humidity 40%
Wind Speed SE 8 mph
Barometer 30.19 in (1022.3 mb)
Dewpoint 41°F (5°C)
Visibility 10.00 mi
Last update 20 Apr 5:53 pm CDT
Extended Forecast for

4 Miles WSW Mascoutah IL

  • Tonight

    Tonight: Mostly clear, with a low around 48. South wind around 7 mph.

    Low: 48 °F

    Mostly Clear

  • Tuesday

    Tuesday: Sunny, with a high near 78. Southwest wind 6 to 14 mph, with gusts as high as 23 mph.

    High: 78 °F

    Sunny

  • Tuesday Night

    Tuesday Night: Mostly clear, with a low around 54. Southwest wind 6 to 10 mph.

    Low: 54 °F

    Mostly Clear

  • Wednesday

    Wednesday: Sunny, with a high near 76. Southwest wind 6 to 8 mph.

    High: 76 °F

    Sunny

  • Wednesday Night

    Wednesday Night: Mostly clear, with a low around 56. South wind around 7 mph.

    Low: 56 °F

    Mostly Clear

  • Thursday

    Thursday: Mostly sunny, with a high near 80.

    High: 80 °F

    Mostly Sunny

  • Thursday Night

    Thursday Night: A 50 percent chance of showers and thunderstorms after 1am. Partly cloudy, with a low around 62.

    Low: 62 °F

    Partly Cloudy
    then Chance
    T-storms

  • Friday

    Friday: Showers and possibly a thunderstorm. High near 75. Chance of precipitation is 90%.

    High: 75 °F

    Showers

  • Friday Night

    Friday Night: A 50 percent chance of showers and thunderstorms. Mostly cloudy, with a low around 53.

    Low: 53 °F

    Chance
    T-storms

Detailed Forecast

Tonight
Mostly clear, with a low around 48. South wind around 7 mph.
Tuesday
Sunny, with a high near 78. Southwest wind 6 to 14 mph, with gusts as high as 23 mph.
Tuesday Night
Mostly clear, with a low around 54. Southwest wind 6 to 10 mph.
Wednesday
Sunny, with a high near 76. Southwest wind 6 to 8 mph.
Wednesday Night
Mostly clear, with a low around 56. South wind around 7 mph.
Thursday
Mostly sunny, with a high near 80.
Thursday Night
A 50 percent chance of showers and thunderstorms after 1am. Partly cloudy, with a low around 62.
Friday
Showers and possibly a thunderstorm. High near 75. Chance of precipitation is 90%.
Friday Night
A 50 percent chance of showers and thunderstorms. Mostly cloudy, with a low around 53.
Saturday
A slight chance of showers, with thunderstorms also possible after 1pm. Mostly sunny, with a high near 73. Chance of precipitation is 20%.
Saturday Night
A 30 percent chance of showers and thunderstorms. Mostly cloudy, with a low around 53.
Sunday
A 30 percent chance of showers and thunderstorms. Partly sunny, with a high near 71.
Sunday Night
A 50 percent chance of showers. Mostly cloudy, with a low around 55.
Monday
A 40 percent chance of showers and thunderstorms. Partly sunny, with a high near 72.
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Forecast Area
Tiles ©ESRI

ABOUT THIS FORECAST

 
Point Forecast:
4 Miles WSW Mascoutah IL
 38.5°N 89.87°W (Elev. 449 ft)
Last Update:
5:51 pm CDT Apr 20, 2026
Forecast Valid:
6pm CDT Apr 20, 2026-6pm CDT Apr 27, 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