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

82°F

28°C

Humidity 67%
Wind Speed S 6 mph
Barometer 29.91 in (1012.2 mb)
Dewpoint 70°F (21°C)
Visibility 10.00 mi
Heat Index86°F (30°C)
Last update 13 Oct 9:53 pm CDT
Extended Forecast for

Granite City IL

  • Tonight

    Tonight: Showers and thunderstorms likely, mainly after 5am. Increasing clouds, with a low around 72. South wind 5 to 7 mph becoming west after midnight. Chance of precipitation is 60%.

    Low: 72 °F

    Clear then
    T-storms
    Likely

  • Wednesday

    Wednesday: Showers and thunderstorms before 11am, then showers likely and possibly a thunderstorm between 11am and 1pm, then a chance of showers and thunderstorms after 1pm. Patchy fog between 9am and 11am. High near 79. North wind 3 to 6 mph. Chance of precipitation is 90%.

    High: 79 °F

    T-storms and
    Patchy Fog
    then Showers
    Likely

  • Wednesday Night

    Wednesday Night: A chance of showers and thunderstorms before 3am, then showers likely between 3am and 4am, then showers likely and possibly a thunderstorm after 4am. Mostly cloudy, with a low around 68. East wind around 7 mph. Chance of precipitation is 70%.

    Low: 68 °F

    Chance
    T-storms then
    Showers
    Likely

  • Thursday

    Thursday: Showers and possibly a thunderstorm. High near 84. East wind 5 to 9 mph becoming southwest in the afternoon. Chance of precipitation is 90%.

    High: 84 °F

    Showers

  • Thursday Night

    Thursday Night: A 40 percent chance of showers and thunderstorms before 1am. Mostly cloudy, with a low around 50. Northwest wind 9 to 17 mph, with gusts as high as 25 mph.

    Low: 50 °F

    Chance
    T-storms then
    Chance
    Showers

  • Friday

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

    High: 63 °F

    Mostly Sunny
    and Breezy

  • Friday Night

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

    Low: 39 °F

    Mostly Clear

  • Saturday

    Saturday: Sunny, with a high near 64.

    High: 64 °F

    Sunny

  • Saturday Night

    Saturday Night: Clear, with a low around 40.

    Low: 40 °F

    Clear

Detailed Forecast

Tonight
Showers and thunderstorms likely, mainly after 5am. Increasing clouds, with a low around 72. South wind 5 to 7 mph becoming west after midnight. Chance of precipitation is 60%.
Wednesday
Showers and thunderstorms before 11am, then showers likely and possibly a thunderstorm between 11am and 1pm, then a chance of showers and thunderstorms after 1pm. Patchy fog between 9am and 11am. High near 79. North wind 3 to 6 mph. Chance of precipitation is 90%.
Wednesday Night
A chance of showers and thunderstorms before 3am, then showers likely between 3am and 4am, then showers likely and possibly a thunderstorm after 4am. Mostly cloudy, with a low around 68. East wind around 7 mph. Chance of precipitation is 70%.
Thursday
Showers and possibly a thunderstorm. High near 84. East wind 5 to 9 mph becoming southwest in the afternoon. Chance of precipitation is 90%.
Thursday Night
A 40 percent chance of showers and thunderstorms before 1am. Mostly cloudy, with a low around 50. Northwest wind 9 to 17 mph, with gusts as high as 25 mph.
Friday
Mostly sunny, with a high near 63. Breezy.
Friday Night
Mostly clear, with a low around 39.
Saturday
Sunny, with a high near 64.
Saturday Night
Clear, with a low around 40.
Sunday
Sunny, with a high near 71.
Sunday Night
Partly cloudy, with a low around 47.
Monday
Mostly sunny, with a high near 75.
Monday Night
Partly cloudy, with a low around 51.
Tuesday
Mostly sunny, with a high near 80.
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Forecast Area
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ABOUT THIS FORECAST

 
Point Forecast:
Granite City IL
 38.71°N 90.14°W (Elev. 410 ft)
Last Update:
9:06 pm CDT Oct 13, 2026
Forecast Valid:
10pm CDT Oct 13, 2026-6pm CDT Oct 20, 2026
 
Forecast Discussion
 
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Additional Resources

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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