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

64°F

18°C

Humidity 81%
Wind Speed S 9 mph
Barometer 29.75 in (1007.3 mb)
Dewpoint 58°F (14°C)
Visibility 10.00 mi
Last update 15 Nov 6:53 am CST
Extended Forecast for

Mascoutah IL

  • Today

    Today: Mostly sunny, with a high near 79. Southwest wind 10 to 15 mph becoming northwest in the afternoon. Winds could gust as high as 24 mph.

    High: 79 °F

    Mostly Sunny

  • Tonight

    Tonight: Mostly clear, with a low around 43. North wind 6 to 10 mph, with gusts as high as 21 mph.

    Low: 43 °F

    Mostly Clear

  • Sunday

    Sunday: Sunny, with a high near 59. North wind 3 to 6 mph.

    High: 59 °F

    Sunny

  • Sunday Night

    Sunday Night: Mostly clear, with a low around 36. Calm wind.

    Low: 36 °F

    Mostly Clear

  • Monday

    Monday: A 20 percent chance of showers after noon. Mostly sunny, with a high near 59. Light east wind becoming southeast 5 to 10 mph in the morning.

    High: 59 °F

    Sunny then
    Slight Chance
    Showers

  • Monday Night

    Monday Night: Showers likely before 9pm, then showers likely and possibly a thunderstorm between 9pm and 3am, then showers likely after 3am. Mostly cloudy, with a low around 46. Chance of precipitation is 70%.

    Low: 46 °F

    Showers
    Likely

  • Tuesday

    Tuesday: Partly sunny, with a high near 67.

    High: 67 °F

    Partly Sunny

  • Tuesday Night

    Tuesday Night: Mostly cloudy, with a low around 45.

    Low: 45 °F

    Mostly Cloudy

  • Wednesday

    Wednesday: A 30 percent chance of rain, mainly after noon. Partly sunny, with a high near 63.

    High: 63 °F

    Chance Rain

Detailed Forecast

Today
Mostly sunny, with a high near 79. Southwest wind 10 to 15 mph becoming northwest in the afternoon. Winds could gust as high as 24 mph.
Tonight
Mostly clear, with a low around 43. North wind 6 to 10 mph, with gusts as high as 21 mph.
Sunday
Sunny, with a high near 59. North wind 3 to 6 mph.
Sunday Night
Mostly clear, with a low around 36. Calm wind.
Monday
A 20 percent chance of showers after noon. Mostly sunny, with a high near 59. Light east wind becoming southeast 5 to 10 mph in the morning.
Monday Night
Showers likely before 9pm, then showers likely and possibly a thunderstorm between 9pm and 3am, then showers likely after 3am. Mostly cloudy, with a low around 46. Chance of precipitation is 70%.
Tuesday
Partly sunny, with a high near 67.
Tuesday Night
Mostly cloudy, with a low around 45.
Wednesday
A 30 percent chance of rain, mainly after noon. Partly sunny, with a high near 63.
Wednesday Night
Rain likely, mainly after midnight. Mostly cloudy, with a low around 50. Chance of precipitation is 60%.
Thursday
Rain and possibly a thunderstorm. High near 64. Chance of precipitation is 80%.
Thursday Night
Rain likely. Mostly cloudy, with a low around 52. Chance of precipitation is 70%.
Friday
A 40 percent chance of rain. Mostly cloudy, with a high near 65.
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Forecast Area
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ABOUT THIS FORECAST

 
Point Forecast:
Mascoutah IL
 38.5°N 89.81°W (Elev. 427 ft)
Last Update:
6:56 am CST Nov 15, 2025
Forecast Valid:
7am CST Nov 15, 2025-6pm CST Nov 21, 2025
 
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