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

65°F

18°C

Humidity 76%
Wind Speed SE 6 mph
Barometer 29.73 in (1006.4 mb)
Dewpoint 57°F (14°C)
Visibility 10.00 mi
Last update 22 Mar 12:53 am CDT
Extended Forecast for

Cahokia IL

  • Overnight

    Overnight: Mostly clear, with a low around 64. South wind around 7 mph.

    Low: 64 °F

    Mostly Clear

  • Sunday

    Sunday: Mostly sunny, with a high near 90. Southwest wind 6 to 13 mph becoming northwest in the afternoon. Winds could gust as high as 22 mph.

    High: 90 °F

    Mostly Sunny

  • Sunday Night

    Sunday Night: Mostly cloudy, then gradually becoming mostly clear, with a low around 39. Breezy, with a north wind 11 to 21 mph, with gusts as high as 31 mph.

    Low: 39 °F

    Mostly Cloudy
    and Breezy
    then Mostly
    Clear

  • Monday

    Monday: Mostly sunny, with a high near 58. Northeast wind 7 to 10 mph.

    High: 58 °F

    Mostly Sunny

  • Monday Night

    Monday Night: Mostly cloudy, with a low around 42. East wind 3 to 5 mph.

    Low: 42 °F

    Mostly Cloudy

  • Tuesday

    Tuesday: Mostly sunny, with a high near 65.

    High: 65 °F

    Mostly Sunny

  • Tuesday Night

    Tuesday Night: Mostly cloudy, with a low around 47.

    Low: 47 °F

    Mostly Cloudy

  • Wednesday

    Wednesday: Partly sunny, with a high near 75.

    High: 75 °F

    Partly Sunny

  • Wednesday Night

    Wednesday Night: A slight chance of rain and thunderstorms. Partly cloudy, with a low around 57. Chance of precipitation is 20%.

    Low: 57 °F

    Slight Chance
    T-storms

Detailed Forecast

Overnight
Mostly clear, with a low around 64. South wind around 7 mph.
Sunday
Mostly sunny, with a high near 90. Southwest wind 6 to 13 mph becoming northwest in the afternoon. Winds could gust as high as 22 mph.
Sunday Night
Mostly cloudy, then gradually becoming mostly clear, with a low around 39. Breezy, with a north wind 11 to 21 mph, with gusts as high as 31 mph.
Monday
Mostly sunny, with a high near 58. Northeast wind 7 to 10 mph.
Monday Night
Mostly cloudy, with a low around 42. East wind 3 to 5 mph.
Tuesday
Mostly sunny, with a high near 65.
Tuesday Night
Mostly cloudy, with a low around 47.
Wednesday
Partly sunny, with a high near 75.
Wednesday Night
A slight chance of rain and thunderstorms. Partly cloudy, with a low around 57. Chance of precipitation is 20%.
Thursday
A 20 percent chance of rain and thunderstorms after 1pm. Sunny, with a high near 86.
Thursday Night
A 40 percent chance of rain and thunderstorms. Partly cloudy, with a low around 46.
Friday
A 40 percent chance of rain. Mostly cloudy, with a high near 58.
Friday Night
A 30 percent chance of rain. Mostly cloudy, with a low around 38.
Saturday
A 20 percent chance of rain. Partly sunny, with a high near 58.
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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:
9:51 pm CDT Mar 21, 2026
Forecast Valid:
1am CDT Mar 22, 2026-6pm CDT Mar 28, 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