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

66°F

19°C

Humidity 40%
Wind Speed SE 8 mph
Barometer 30.19 in (1022.3 mb)
Dewpoint 41°F (5°C)
Visibility 10.00 mi
Last update 20 Apr 5:53 pm CDT
Extended Forecast for

Granite City IL

  • Tonight

    Tonight: Mostly clear, with a low around 50. South wind 6 to 8 mph.

    Low: 50 °F

    Mostly Clear

  • Tuesday

    Tuesday: Sunny, with a high near 80. Southwest wind 6 to 14 mph, with gusts as high as 24 mph.

    High: 80 °F

    Sunny

  • Tuesday Night

    Tuesday Night: Mostly clear, with a low around 57. Southwest wind 7 to 11 mph.

    Low: 57 °F

    Mostly Clear

  • Wednesday

    Wednesday: Sunny, with a high near 78. Southwest wind 6 to 8 mph.

    High: 78 °F

    Sunny

  • Wednesday Night

    Wednesday Night: Mostly clear, with a low around 58. South wind around 6 mph.

    Low: 58 °F

    Mostly Clear

  • Thursday

    Thursday: Mostly sunny, with a high near 83.

    High: 83 °F

    Mostly Sunny

  • Thursday Night

    Thursday Night: Showers likely and possibly a thunderstorm after 1am. Mostly cloudy, with a low around 63. Chance of precipitation is 60%.

    Low: 63 °F

    Partly Cloudy
    then Showers
    Likely

  • Friday

    Friday: Showers and possibly a thunderstorm. High near 76. Chance of precipitation is 80%.

    High: 76 °F

    Showers

  • Friday Night

    Friday Night: A chance of showers and thunderstorms. Mostly cloudy, with a low around 54. Chance of precipitation is 50%.

    Low: 54 °F

    Chance
    T-storms

Detailed Forecast

Tonight
Mostly clear, with a low around 50. South wind 6 to 8 mph.
Tuesday
Sunny, with a high near 80. Southwest wind 6 to 14 mph, with gusts as high as 24 mph.
Tuesday Night
Mostly clear, with a low around 57. Southwest wind 7 to 11 mph.
Wednesday
Sunny, with a high near 78. Southwest wind 6 to 8 mph.
Wednesday Night
Mostly clear, with a low around 58. South wind around 6 mph.
Thursday
Mostly sunny, with a high near 83.
Thursday Night
Showers likely and possibly a thunderstorm after 1am. Mostly cloudy, with a low around 63. Chance of precipitation is 60%.
Friday
Showers and possibly a thunderstorm. High near 76. Chance of precipitation is 80%.
Friday Night
A chance of showers and thunderstorms. Mostly cloudy, with a low around 54. Chance of precipitation is 50%.
Saturday
A 20 percent chance of showers. Mostly sunny, with a high near 74.
Saturday Night
A 30 percent chance of showers and thunderstorms. Mostly cloudy, with a low around 53.
Sunday
A 30 percent chance of showers and thunderstorms. Partly sunny, with a high near 73.
Sunday Night
A 50 percent chance of showers. Mostly cloudy, with a low around 55.
Monday
A 40 percent chance of showers and thunderstorms. Partly sunny, with a high near 72.
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Forecast Area
Tiles ©ESRI

ABOUT THIS FORECAST

 
Point Forecast:
Granite City IL
 38.73°N 90.11°W (Elev. 417 ft)
Last Update:
5:51 pm CDT Apr 20, 2026
Forecast Valid:
6pm CDT Apr 20, 2026-6pm CDT Apr 27, 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