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

67°F

19°C

Humidity 45%
Wind Speed NE 3 mph
Barometer 29.89 in (1011.8 mb)
Dewpoint 45°F (7°C)
Visibility 10.00 mi
Last update 20 Mar 10:53 pm CDT
Extended Forecast for

Cahokia IL

  • Tonight

    Tonight: Partly cloudy, with a low around 53. Calm wind.

    Low: 53 °F

    Partly Cloudy

  • Saturday

    Saturday: Sunny, with a high near 86. Calm wind becoming south around 5 mph in the afternoon.

    High: 86 °F

    Sunny

  • Saturday Night

    Saturday Night: Mostly clear, with a low around 64. Southwest wind 5 to 7 mph.

    Low: 64 °F

    Mostly Clear

  • Sunday

    Sunday: Increasing clouds, with a high near 87. Southwest wind 7 to 13 mph becoming northwest in the afternoon. Winds could gust as high as 21 mph.

    High: 87 °F

    Increasing
    Clouds

  • Sunday Night

    Sunday Night: Partly cloudy, with a low around 41. North wind 10 to 15 mph, with gusts as high as 26 mph.

    Low: 41 °F

    Partly Cloudy

  • Monday

    Monday: Mostly sunny, with a high near 59.

    High: 59 °F

    Mostly Sunny

  • Monday Night

    Monday Night: Partly cloudy, with a low around 41.

    Low: 41 °F

    Partly Cloudy

  • Tuesday

    Tuesday: Partly sunny, with a high near 61.

    High: 61 °F

    Partly Sunny

  • Tuesday Night

    Tuesday Night: A 20 percent chance of rain and thunderstorms after 1am. Partly cloudy, with a low around 44.

    Low: 44 °F

    Partly Cloudy
    then Slight
    Chance
    T-storms

Detailed Forecast

Tonight
Partly cloudy, with a low around 53. Calm wind.
Saturday
Sunny, with a high near 86. Calm wind becoming south around 5 mph in the afternoon.
Saturday Night
Mostly clear, with a low around 64. Southwest wind 5 to 7 mph.
Sunday
Increasing clouds, with a high near 87. Southwest wind 7 to 13 mph becoming northwest in the afternoon. Winds could gust as high as 21 mph.
Sunday Night
Partly cloudy, with a low around 41. North wind 10 to 15 mph, with gusts as high as 26 mph.
Monday
Mostly sunny, with a high near 59.
Monday Night
Partly cloudy, with a low around 41.
Tuesday
Partly sunny, with a high near 61.
Tuesday Night
A 20 percent chance of rain and thunderstorms after 1am. Partly cloudy, with a low around 44.
Wednesday
Partly sunny, with a high near 68.
Wednesday Night
Partly cloudy, with a low around 52.
Thursday
A 20 percent chance of rain. Sunny, with a high near 80.
Thursday Night
A 40 percent chance of rain. Partly cloudy, with a low around 42.
Friday
A 30 percent chance of rain. Mostly cloudy, with a high near 55.
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Forecast Area
Tiles ©ESRI

ABOUT THIS FORECAST

 
Point Forecast:
Cahokia IL
 38.57°N 90.18°W (Elev. 407 ft)
Last Update:
10:26 pm CDT Mar 20, 2026
Forecast Valid:
11pm CDT Mar 20, 2026-6pm CDT Mar 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