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.

A Few Clouds

93°F

34°C

Humidity 46%
Wind Speed S 9 mph
Barometer 29.87 in (1011.1 mb)
Dewpoint 69°F (21°C)
Visibility 10.00 mi
Heat Index98°F (37°C)
Last update 13 Oct 2:53 pm CDT
Extended Forecast for

Granite City IL

  • Tonight

    Tonight: A chance of showers and thunderstorms, then showers likely and possibly a thunderstorm after 5am. Increasing clouds, with a low around 72. South wind 5 to 8 mph. Chance of precipitation is 60%.

    Low: 72 °F

    Mostly Clear
    then Showers
    Likely

  • Wednesday

    Wednesday: Showers and possibly a thunderstorm, mainly before 1pm, then a chance of showers and thunderstorms after 1pm. Patchy fog between 8am and 11am. High near 79. Light and variable wind becoming west around 5 mph in the afternoon. Chance of precipitation is 90%.

    High: 79 °F

    Showers 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. Light and variable wind. Chance of precipitation is 70%.

    Low: 68 °F

    Chance
    T-storms then
    Showers
    Likely

  • Thursday

    Thursday: Showers and possibly a thunderstorm. High near 84. Light and variable wind becoming southwest 5 to 9 mph in the morning. 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
A chance of showers and thunderstorms, then showers likely and possibly a thunderstorm after 5am. Increasing clouds, with a low around 72. South wind 5 to 8 mph. Chance of precipitation is 60%.
Wednesday
Showers and possibly a thunderstorm, mainly before 1pm, then a chance of showers and thunderstorms after 1pm. Patchy fog between 8am and 11am. High near 79. Light and variable wind becoming west around 5 mph in the afternoon. 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. Light and variable wind. Chance of precipitation is 70%.
Thursday
Showers and possibly a thunderstorm. High near 84. Light and variable wind becoming southwest 5 to 9 mph in the morning. 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:
3:01 pm CDT Oct 13, 2026
Forecast Valid:
3pm CDT Oct 13, 2026-6pm CDT Oct 20, 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