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.

N/A

Humidity NA
Wind Speed NA
Barometer NA
Dewpoint N/A
Visibility NA
Last update *** Not a current observation ***
Extended Forecast for

Cahokia IL

  • Overnight

    Overnight: Patchy fog after 4am. Otherwise, partly cloudy, with a low around 35. West wind around 5 mph becoming calm.

    Low: 35 °F

    Patchy Fog

  • Sunday

    Sunday: Patchy fog before 7am. Otherwise, sunny, with a high near 67. Calm wind becoming southwest 5 to 8 mph in the morning.

    High: 67 °F

    Patchy Fog
    then Sunny

  • Sunday Night

    Sunday Night: Clear, with a low around 45. Southwest wind around 6 mph.

    Low: 45 °F

    Clear

  • Monday

    Monday: Sunny, with a high near 78. South wind 6 to 13 mph, with gusts as high as 22 mph.

    High: 78 °F

    Sunny

  • Monday Night

    Monday Night: Mostly clear, with a low around 61. South wind 6 to 10 mph, with gusts as high as 20 mph.

    Low: 61 °F

    Mostly Clear

  • Tuesday

    Tuesday: Rain likely, with thunderstorms also possible after 3pm. Mostly cloudy, with a high near 82. Chance of precipitation is 60%.

    High: 82 °F

    Slight Chance
    Rain then
    Rain Likely

  • Tuesday Night

    Tuesday Night: Rain and possibly a thunderstorm. Low around 56. Chance of precipitation is 90%.

    Low: 56 °F

    Rain

  • Wednesday

    Wednesday: Rain and possibly a thunderstorm before noon, then a chance of rain. High near 68. Chance of precipitation is 100%.

    High: 68 °F

    Rain then
    Chance Rain

  • Wednesday Night

    Wednesday Night: A 20 percent chance of rain before midnight. Partly cloudy, with a low around 33.

    Low: 33 °F

    Slight Chance
    Rain then
    Mostly Clear

Detailed Forecast

Overnight
Patchy fog after 4am. Otherwise, partly cloudy, with a low around 35. West wind around 5 mph becoming calm.
Sunday
Patchy fog before 7am. Otherwise, sunny, with a high near 67. Calm wind becoming southwest 5 to 8 mph in the morning.
Sunday Night
Clear, with a low around 45. Southwest wind around 6 mph.
Monday
Sunny, with a high near 78. South wind 6 to 13 mph, with gusts as high as 22 mph.
Monday Night
Mostly clear, with a low around 61. South wind 6 to 10 mph, with gusts as high as 20 mph.
Tuesday
Rain likely, with thunderstorms also possible after 3pm. Mostly cloudy, with a high near 82. Chance of precipitation is 60%.
Tuesday Night
Rain and possibly a thunderstorm. Low around 56. Chance of precipitation is 90%.
Wednesday
Rain and possibly a thunderstorm before noon, then a chance of rain. High near 68. Chance of precipitation is 100%.
Wednesday Night
A 20 percent chance of rain before midnight. Partly cloudy, with a low around 33.
Thursday
Sunny, with a high near 55.
Thursday Night
Mostly cloudy, with a low around 45.
Friday
Partly sunny, with a high near 68.
Friday Night
Mostly cloudy, with a low around 38.
Saturday
Partly sunny, with a high near 57.
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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:
12:26 am CST Mar 8, 2026
Forecast Valid:
1am CST Mar 8, 2026-6pm CDT Mar 14, 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