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

40°F

4°C

Humidity 68%
Wind Speed S 3 mph
Barometer 30.08 in (1018.4 mb)
Dewpoint 30°F (-1°C)
Visibility 10.00 mi
Last update 13 Mar 11:53 pm CDT
Extended Forecast for

Granite City IL

  • Tonight

    Tonight: Partly cloudy, with a low around 37. Calm wind becoming northeast around 5 mph after midnight.

    Low: 37 °F

    Partly Cloudy

  • Saturday

    Saturday: Mostly sunny, with a high near 64. East wind 6 to 15 mph becoming southeast in the afternoon. Winds could gust as high as 22 mph.

    High: 64 °F

    Mostly Sunny

  • Saturday Night

    Saturday Night: Partly cloudy, with a low around 55. Southeast wind 10 to 15 mph, with gusts as high as 25 mph.

    Low: 55 °F

    Partly Cloudy

  • Sunday

    Sunday: A chance of rain and thunderstorms before 1pm, then rain between 1pm and 4pm, then showers and possibly a thunderstorm after 4pm. High near 69. Breezy, with a south wind 18 to 23 mph, with gusts as high as 38 mph. Chance of precipitation is 90%.

    High: 69 °F

    Breezy.
    Chance Rain
    then Showers

  • Sunday Night

    Sunday Night: Rain before 10pm, then snow, possibly mixed with rain between 10pm and 1am, then a chance of snow after 1am. Some thunder is also possible. Low around 23. Blustery, with a west wind 21 to 25 mph, with gusts as high as 43 mph. Chance of precipitation is 90%. New snow accumulation of less than one inch possible.

    Low: 23 °F

    Rain/Snow and
    Blustery

  • Monday

    Monday: A 30 percent chance of snow before 1pm. Mostly cloudy, with a high near 29. Blustery.

    High: 29 °F

    Chance Snow
    and Blustery

  • Monday Night

    Monday Night: Mostly clear, with a low around 14.

    Low: 14 °F

    Mostly Clear

  • Tuesday

    Tuesday: Sunny, with a high near 36.

    High: 36 °F

    Sunny

  • Tuesday Night

    Tuesday Night: A slight chance of snow before 1am, then a chance of rain and snow. Mostly cloudy, with a low around 29. Chance of precipitation is 30%.

    Low: 29 °F

    Slight Chance
    Snow then
    Chance
    Rain/Snow

Detailed Forecast

Tonight
Partly cloudy, with a low around 37. Calm wind becoming northeast around 5 mph after midnight.
Saturday
Mostly sunny, with a high near 64. East wind 6 to 15 mph becoming southeast in the afternoon. Winds could gust as high as 22 mph.
Saturday Night
Partly cloudy, with a low around 55. Southeast wind 10 to 15 mph, with gusts as high as 25 mph.
Sunday
A chance of rain and thunderstorms before 1pm, then rain between 1pm and 4pm, then showers and possibly a thunderstorm after 4pm. High near 69. Breezy, with a south wind 18 to 23 mph, with gusts as high as 38 mph. Chance of precipitation is 90%.
Sunday Night
Rain before 10pm, then snow, possibly mixed with rain between 10pm and 1am, then a chance of snow after 1am. Some thunder is also possible. Low around 23. Blustery, with a west wind 21 to 25 mph, with gusts as high as 43 mph. Chance of precipitation is 90%. New snow accumulation of less than one inch possible.
Monday
A 30 percent chance of snow before 1pm. Mostly cloudy, with a high near 29. Blustery.
Monday Night
Mostly clear, with a low around 14.
Tuesday
Sunny, with a high near 36.
Tuesday Night
A slight chance of snow before 1am, then a chance of rain and snow. Mostly cloudy, with a low around 29. Chance of precipitation is 30%.
Wednesday
A 20 percent chance of rain before 1pm. Mostly sunny, with a high near 64.
Wednesday Night
Mostly clear, with a low around 41.
Thursday
Mostly sunny, with a high near 69.
Thursday Night
Mostly clear, with a low around 46.
Friday
Sunny, with a high near 69.
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Forecast Area
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ABOUT THIS FORECAST

 
Point Forecast:
Granite City IL
 38.73°N 90.11°W (Elev. 417 ft)
Last Update:
11:46 pm CDT Mar 13, 2026
Forecast Valid:
11pm CDT Mar 13, 2026-6pm CDT Mar 20, 2026
 
Forecast Discussion
 
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Additional Resources

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High Temperature

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Chance of Precipitation