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

69°F

21°C

Humidity 70%
Wind Speed E 6 mph
Barometer 30.14 in (1020.4 mb)
Dewpoint 59°F (15°C)
Visibility 10.00 mi
Last update 23 Jun 9:53 pm CDT
Extended Forecast for

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

  • Tonight

    Tonight: Mostly cloudy, with a low around 63. Light southeast wind.

    Low: 63 °F

    Mostly Cloudy

  • Wednesday

    Wednesday: A 20 percent chance of showers and thunderstorms after 3pm. Partly sunny, with a high near 84. South wind 3 to 7 mph.

    High: 84 °F

    Partly Sunny
    then Slight
    Chance
    T-storms

  • Wednesday Night

    Wednesday Night: A chance of showers and thunderstorms. Partly cloudy, with a low around 66. South wind around 6 mph becoming calm in the evening. Chance of precipitation is 40%.

    Low: 66 °F

    Slight Chance
    T-storms then
    Chance
    Showers

  • Thursday

    Thursday: A slight chance of showers before 1pm, then showers likely and possibly a thunderstorm between 1pm and 4pm, then showers and thunderstorms likely after 4pm. Patchy fog before 8am. Otherwise, increasing clouds, with a high near 86. Calm wind becoming south around 5 mph in the afternoon. Chance of precipitation is 70%.

    High: 86 °F

    Patchy Fog
    then T-storms
    Likely

  • Thursday Night

    Thursday Night: Showers and possibly a thunderstorm. Low around 67. East wind around 5 mph becoming calm in the evening. Chance of precipitation is 90%.

    Low: 67 °F

    T-storms then
    Showers

  • Friday

    Friday: Showers and possibly a thunderstorm before 1pm, then showers and thunderstorms likely after 1pm. High near 83. Chance of precipitation is 80%.

    High: 83 °F

    Showers then
    T-storms

  • Friday Night

    Friday Night: Showers likely and possibly a thunderstorm. Mostly cloudy, with a low around 71. Chance of precipitation is 60%.

    Low: 71 °F

    Showers
    Likely

  • Saturday

    Saturday: A 40 percent chance of showers and thunderstorms. Partly sunny, with a high near 90.

    High: 90 °F

    Chance
    T-storms

  • Saturday Night

    Saturday Night: A 20 percent chance of showers and thunderstorms. Partly cloudy, with a low around 74.

    Low: 74 °F

    Slight Chance
    T-storms

Detailed Forecast

Tonight
Mostly cloudy, with a low around 63. Light southeast wind.
Wednesday
A 20 percent chance of showers and thunderstorms after 3pm. Partly sunny, with a high near 84. South wind 3 to 7 mph.
Wednesday Night
A chance of showers and thunderstorms. Partly cloudy, with a low around 66. South wind around 6 mph becoming calm in the evening. Chance of precipitation is 40%.
Thursday
A slight chance of showers before 1pm, then showers likely and possibly a thunderstorm between 1pm and 4pm, then showers and thunderstorms likely after 4pm. Patchy fog before 8am. Otherwise, increasing clouds, with a high near 86. Calm wind becoming south around 5 mph in the afternoon. Chance of precipitation is 70%.
Thursday Night
Showers and possibly a thunderstorm. Low around 67. East wind around 5 mph becoming calm in the evening. Chance of precipitation is 90%.
Friday
Showers and possibly a thunderstorm before 1pm, then showers and thunderstorms likely after 1pm. High near 83. Chance of precipitation is 80%.
Friday Night
Showers likely and possibly a thunderstorm. Mostly cloudy, with a low around 71. Chance of precipitation is 60%.
Saturday
A 40 percent chance of showers and thunderstorms. Partly sunny, with a high near 90.
Saturday Night
A 20 percent chance of showers and thunderstorms. Partly cloudy, with a low around 74.
Sunday
Mostly sunny and hot, with a high near 97.
Sunday Night
Mostly clear, with a low around 76.
Monday
Sunny and hot, with a high near 97.
Monday Night
Mostly clear, with a low around 77.
Tuesday
Sunny and hot, with a high near 99.
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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:
9:26 pm CDT Jun 23, 2026
Forecast Valid:
10pm CDT Jun 23, 2026-6pm CDT Jun 30, 2026
 
Forecast Discussion
 
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Additional Resources

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High Temperature

National Digital Forecast Database Weather Element Forecast

Chance of Precipitation