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

43°F

6°C

Humidity 63%
Wind Speed Calm
Barometer 30.39 in (1029.2 mb)
Dewpoint 31°F (-1°C)
Visibility 10.00 mi
Last update 23 Mar 11:53 pm CDT
Extended Forecast for

Granite City IL

  • Overnight

    Overnight: Mostly cloudy, with a low around 37. East wind around 6 mph.

    Low: 37 °F

    Mostly Cloudy

  • Tuesday

    Tuesday: Mostly sunny, with a high near 63. Southeast wind 6 to 8 mph.

    High: 63 °F

    Mostly Sunny

  • Tuesday Night

    Tuesday Night: Mostly cloudy, with a low around 45. Southeast wind 3 to 6 mph.

    Low: 45 °F

    Mostly Cloudy

  • Wednesday

    Wednesday: Mostly sunny, with a high near 78. Light southeast wind becoming south 5 to 10 mph in the morning.

    High: 78 °F

    Mostly Sunny

  • Wednesday Night

    Wednesday Night: Mostly clear, with a low around 63. South wind around 9 mph.

    Low: 63 °F

    Mostly Clear

  • Thursday

    Thursday: Sunny, with a high near 90.

    High: 90 °F

    Sunny

  • Thursday Night

    Thursday Night: A chance of showers and thunderstorms, then showers and possibly a thunderstorm after 1am. Low around 43. Breezy. Chance of precipitation is 80%.

    Low: 43 °F

    Chance
    T-storms then
    Showers and
    Breezy

  • Friday

    Friday: A chance of showers before 1pm, then a slight chance of rain after 1pm. Mostly cloudy, with a high near 53. Chance of precipitation is 40%.

    High: 53 °F

    Chance
    Showers

  • Friday Night

    Friday Night: Partly cloudy, with a low around 33.

    Low: 33 °F

    Partly Cloudy

Detailed Forecast

Overnight
Mostly cloudy, with a low around 37. East wind around 6 mph.
Tuesday
Mostly sunny, with a high near 63. Southeast wind 6 to 8 mph.
Tuesday Night
Mostly cloudy, with a low around 45. Southeast wind 3 to 6 mph.
Wednesday
Mostly sunny, with a high near 78. Light southeast wind becoming south 5 to 10 mph in the morning.
Wednesday Night
Mostly clear, with a low around 63. South wind around 9 mph.
Thursday
Sunny, with a high near 90.
Thursday Night
A chance of showers and thunderstorms, then showers and possibly a thunderstorm after 1am. Low around 43. Breezy. Chance of precipitation is 80%.
Friday
A chance of showers before 1pm, then a slight chance of rain after 1pm. Mostly cloudy, with a high near 53. Chance of precipitation is 40%.
Friday Night
Partly cloudy, with a low around 33.
Saturday
Sunny, with a high near 58.
Saturday Night
Partly cloudy, with a low around 38.
Sunday
Mostly sunny, with a high near 64.
Sunday Night
Mostly cloudy, with a low around 47.
Monday
A 20 percent chance of rain. Mostly sunny, with a high near 72.
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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:
10:21 pm CDT Mar 23, 2026
Forecast Valid:
12am CDT Mar 24, 2026-6pm CDT Mar 30, 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