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

78°F

26°C

Humidity 52%
Wind Speed S 3 mph
Barometer 29.86 in (1010.9 mb)
Dewpoint 59°F (15°C)
Visibility 10.00 mi
Heat Index79°F (26°C)
Last update 12 Oct 8:53 pm CDT
Extended Forecast for

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

  • Tonight

    Tonight: Mostly clear, with a low around 68. Southwest wind 3 to 8 mph.

    Low: 68 °F

    Mostly Clear

  • Tuesday

    Tuesday: Sunny, with a high near 95. Heat index values as high as 100. Southwest wind 6 to 9 mph.

    High: 95 °F

    Sunny

  • Tuesday Night

    Tuesday Night: A chance of showers and thunderstorms, then showers likely and possibly a thunderstorm after 5am. Partly cloudy, with a low around 71. South wind 5 to 8 mph. Chance of precipitation is 60%.

    Low: 71 °F

    Mostly Clear
    then Showers
    Likely

  • Wednesday

    Wednesday: Showers and possibly a thunderstorm. High near 81. Calm wind becoming west around 6 mph. Chance of precipitation is 100%.

    High: 81 °F

    Showers

  • Wednesday Night

    Wednesday Night: A chance of showers and thunderstorms, then showers likely and possibly a thunderstorm after 1am. Mostly cloudy, with a low around 64. Light and variable wind. Chance of precipitation is 60%.

    Low: 64 °F

    Showers
    Likely

  • Thursday

    Thursday: Showers and possibly a thunderstorm. High near 82. Chance of precipitation is 80%.

    High: 82 °F

    Showers

  • Thursday Night

    Thursday Night: A chance of showers and thunderstorms before 1am, then a slight chance of showers. Mostly cloudy, with a low around 50. Chance of precipitation is 30%.

    Low: 50 °F

    Chance
    Showers

  • Friday

    Friday: Partly sunny, with a high near 63. Breezy.

    High: 63 °F

    Partly Sunny
    and Breezy

  • Friday Night

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

    Low: 39 °F

    Mostly Clear

Detailed Forecast

Tonight
Mostly clear, with a low around 68. Southwest wind 3 to 8 mph.
Tuesday
Sunny, with a high near 95. Heat index values as high as 100. Southwest wind 6 to 9 mph.
Tuesday Night
A chance of showers and thunderstorms, then showers likely and possibly a thunderstorm after 5am. Partly cloudy, with a low around 71. South wind 5 to 8 mph. Chance of precipitation is 60%.
Wednesday
Showers and possibly a thunderstorm. High near 81. Calm wind becoming west around 6 mph. Chance of precipitation is 100%.
Wednesday Night
A chance of showers and thunderstorms, then showers likely and possibly a thunderstorm after 1am. Mostly cloudy, with a low around 64. Light and variable wind. Chance of precipitation is 60%.
Thursday
Showers and possibly a thunderstorm. High near 82. Chance of precipitation is 80%.
Thursday Night
A chance of showers and thunderstorms before 1am, then a slight chance of showers. Mostly cloudy, with a low around 50. Chance of precipitation is 30%.
Friday
Partly sunny, with a high near 63. Breezy.
Friday Night
Mostly clear, with a low around 39.
Saturday
Sunny, with a high near 62.
Saturday Night
Mostly clear, with a low around 37.
Sunday
Sunny, with a high near 71.
Sunday Night
Partly cloudy, with a low around 44.
Monday
Mostly sunny, with a high near 76.
Basemap Options
Click map to change the forecast location
Loading map...
Forecast Area
Tiles ©ESRI

ABOUT THIS FORECAST

 
Point Forecast:
Cahokia / St. Louis, St. Louis Downtown Airport IL
 38.57°N 90.15°W (Elev. 407 ft)
Last Update:
8:41 pm CDT Oct 12, 2026
Forecast Valid:
8pm CDT Oct 12, 2026-6pm CDT Oct 19, 2026
 
Forecast Discussion
 
Get as KML Get as XML

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