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

56°F

13°C

Humidity 36%
Wind Speed SE 14 mph
Barometer 30.15 in (1021.1 mb)
Dewpoint 29°F (-2°C)
Visibility 10.00 mi
Last update 24 Mar 9:53 pm CDT
Extended Forecast for

Cahokia / St. Louis, St. Louis Downtown Airport IL

  • Tonight

    Tonight: Mostly cloudy, with a low around 42. Southeast wind 3 to 6 mph.

    Low: 42 °F

    Mostly Cloudy

  • Wednesday

    Wednesday: Mostly sunny, with a high near 78. Light south wind increasing to 6 to 11 mph in the morning.

    High: 78 °F

    Mostly Sunny

  • Wednesday Night

    Wednesday Night: Mostly clear, with a low around 61. South wind around 10 mph.

    Low: 61 °F

    Mostly Clear

  • Thursday

    Thursday: Sunny, with a high near 90. Southwest wind 10 to 14 mph, with gusts as high as 23 mph.

    High: 90 °F

    Sunny

  • Thursday Night

    Thursday Night: Rain, mainly after 1am. Low around 44. Southwest wind 10 to 15 mph becoming north after midnight. Winds could gust as high as 24 mph. Chance of precipitation is 90%.

    Low: 44 °F

    Chance Rain
    then Rain

  • Friday

    Friday: A 40 percent chance of rain before 1pm. Partly sunny, with a high near 53.

    High: 53 °F

    Chance Rain

  • Friday Night

    Friday Night: Mostly clear, with a low around 31.

    Low: 31 °F

    Mostly Clear

  • Saturday

    Saturday: Sunny, with a high near 59.

    High: 59 °F

    Sunny

  • Saturday Night

    Saturday Night: Mostly clear, with a low around 39.

    Low: 39 °F

    Mostly Clear

Detailed Forecast

Tonight
Mostly cloudy, with a low around 42. Southeast wind 3 to 6 mph.
Wednesday
Mostly sunny, with a high near 78. Light south wind increasing to 6 to 11 mph in the morning.
Wednesday Night
Mostly clear, with a low around 61. South wind around 10 mph.
Thursday
Sunny, with a high near 90. Southwest wind 10 to 14 mph, with gusts as high as 23 mph.
Thursday Night
Rain, mainly after 1am. Low around 44. Southwest wind 10 to 15 mph becoming north after midnight. Winds could gust as high as 24 mph. Chance of precipitation is 90%.
Friday
A 40 percent chance of rain before 1pm. Partly sunny, with a high near 53.
Friday Night
Mostly clear, with a low around 31.
Saturday
Sunny, with a high near 59.
Saturday Night
Mostly clear, with a low around 39.
Sunday
Partly sunny, with a high near 65.
Sunday Night
Mostly cloudy, with a low around 49.
Monday
Mostly sunny, with a high near 78.
Monday Night
A 30 percent chance of rain. Mostly cloudy, with a low around 56.
Tuesday
A 40 percent chance of rain and thunderstorms. Partly sunny, with a high near 78.
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ABOUT THIS FORECAST

 
Point Forecast:
Cahokia / St. Louis, St. Louis Downtown Airport IL
 38.57°N 90.15°W (Elev. 407 ft)
Last Update:
8:51 pm CDT Mar 24, 2026
Forecast Valid:
10pm CDT Mar 24, 2026-6pm CDT Mar 31, 2026
 
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Additional Resources

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Hourly Weather Forecast

National Digital Forecast Database

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High Temperature

National Digital Forecast Database Weather Element Forecast

Chance of Precipitation