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

60°F

16°C

Humidity 25%
Wind Speed N 15 mph
Barometer 29.96 in (1014.6 mb)
Dewpoint 24°F (-4°C)
Visibility 10.00 mi
Last update 13 Mar 5:53 pm CDT
Extended Forecast for

3 Miles SW Mascoutah IL

  • Tonight

    Tonight: Partly cloudy, with a low around 35. Northwest wind 5 to 8 mph becoming calm in the evening.

    Low: 35 °F

    Partly Cloudy

  • Saturday

    Saturday: Mostly sunny, with a high near 63. East wind 6 to 13 mph becoming south in the afternoon. Winds could gust as high as 20 mph.

    High: 63 °F

    Mostly Sunny

  • Saturday Night

    Saturday Night: Partly cloudy, with a low around 54. Southeast wind 9 to 15 mph, with gusts as high as 25 mph.

    Low: 54 °F

    Partly Cloudy

  • Sunday

    Sunday: Rain, mainly between 1pm and 4pm, then showers and possibly a thunderstorm after 4pm. High near 68. Breezy, with a south wind 20 to 24 mph, with gusts as high as 38 mph. Chance of precipitation is 80%.

    High: 68 °F

    Breezy.
    Chance Rain
    then Showers

  • Sunday Night

    Sunday Night: Rain before 10pm, then snow, possibly mixed with rain between 10pm and 1am, then a chance of snow after 1am. Some thunder is also possible. Low around 23. Breezy, with a west wind 21 to 25 mph, with gusts as high as 41 mph. Chance of precipitation is 90%. New snow accumulation of less than one inch possible.

    Low: 23 °F

    Rain/Snow and
    Breezy

  • Monday

    Monday: A 30 percent chance of snow before 1pm. Mostly cloudy, with a high near 28. Blustery.

    High: 28 °F

    Chance Snow
    and Blustery

  • Monday Night

    Monday Night: Mostly clear, with a low around 14.

    Low: 14 °F

    Mostly Clear

  • Tuesday

    Tuesday: Sunny, with a high near 36.

    High: 36 °F

    Sunny

  • Tuesday Night

    Tuesday Night: A slight chance of rain and snow after 1am. Mostly cloudy, with a low around 29. Chance of precipitation is 20%.

    Low: 29 °F

    Mostly Cloudy
    then Slight
    Chance
    Rain/Snow

Detailed Forecast

Tonight
Partly cloudy, with a low around 35. Northwest wind 5 to 8 mph becoming calm in the evening.
Saturday
Mostly sunny, with a high near 63. East wind 6 to 13 mph becoming south in the afternoon. Winds could gust as high as 20 mph.
Saturday Night
Partly cloudy, with a low around 54. Southeast wind 9 to 15 mph, with gusts as high as 25 mph.
Sunday
Rain, mainly between 1pm and 4pm, then showers and possibly a thunderstorm after 4pm. High near 68. Breezy, with a south wind 20 to 24 mph, with gusts as high as 38 mph. Chance of precipitation is 80%.
Sunday Night
Rain before 10pm, then snow, possibly mixed with rain between 10pm and 1am, then a chance of snow after 1am. Some thunder is also possible. Low around 23. Breezy, with a west wind 21 to 25 mph, with gusts as high as 41 mph. Chance of precipitation is 90%. New snow accumulation of less than one inch possible.
Monday
A 30 percent chance of snow before 1pm. Mostly cloudy, with a high near 28. Blustery.
Monday Night
Mostly clear, with a low around 14.
Tuesday
Sunny, with a high near 36.
Tuesday Night
A slight chance of rain and snow after 1am. Mostly cloudy, with a low around 29. Chance of precipitation is 20%.
Wednesday
Mostly sunny, with a high near 61.
Wednesday Night
Mostly clear, with a low around 40.
Thursday
Mostly sunny, with a high near 68.
Thursday Night
Mostly clear, with a low around 45.
Friday
Sunny, with a high near 67.
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Forecast Area
Tiles ©ESRI

ABOUT THIS FORECAST

 
Point Forecast:
3 Miles SW Mascoutah IL
 38.48°N 89.84°W (Elev. 400 ft)
Last Update:
6:16 pm CDT Mar 13, 2026
Forecast Valid:
6pm CDT Mar 13, 2026-6pm CDT Mar 20, 2026
 
Forecast Discussion
 
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Additional Resources

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High Temperature

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Chance of Precipitation