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

60°F

16°C

Humidity 84%
Wind Speed Calm
Barometer 29.72 in (1005.9 mb)
Dewpoint 55°F (13°C)
Visibility 10.00 mi
Last update 22 Mar 1:53 am CDT
Extended Forecast for

Granite City IL

  • Overnight

    Overnight: Clear, with a low around 64. South wind around 8 mph.

    Low: 64 °F

    Clear

  • Sunday

    Sunday: Increasing clouds, with a high near 89. South wind 7 to 15 mph becoming northwest in the afternoon.

    High: 89 °F

    Increasing
    Clouds

  • Sunday Night

    Sunday Night: A 20 percent chance of showers and thunderstorms before 10pm. Mostly cloudy during the early evening, then gradual clearing, with a low around 37. Breezy, with a north wind 17 to 22 mph decreasing to 11 to 16 mph after midnight. Winds could gust as high as 37 mph.

    Low: 37 °F

    Slight Chance
    T-storms and
    Breezy then
    Mostly Clear

  • Monday

    Monday: Mostly sunny, with a high near 56. North wind around 10 mph.

    High: 56 °F

    Mostly Sunny

  • Monday Night

    Monday Night: Mostly cloudy, with a low around 39. Northeast wind around 6 mph.

    Low: 39 °F

    Mostly Cloudy

  • Tuesday

    Tuesday: Mostly sunny, with a high near 66.

    High: 66 °F

    Mostly Sunny

  • Tuesday Night

    Tuesday Night: Mostly cloudy, with a low around 47.

    Low: 47 °F

    Mostly Cloudy

  • Wednesday

    Wednesday: Partly sunny, with a high near 77.

    High: 77 °F

    Partly Sunny

  • Wednesday Night

    Wednesday Night: A 20 percent chance of rain and thunderstorms. Partly cloudy, with a low around 61.

    Low: 61 °F

    Slight Chance
    T-storms

Detailed Forecast

Overnight
Clear, with a low around 64. South wind around 8 mph.
Sunday
Increasing clouds, with a high near 89. South wind 7 to 15 mph becoming northwest in the afternoon.
Sunday Night
A 20 percent chance of showers and thunderstorms before 10pm. Mostly cloudy during the early evening, then gradual clearing, with a low around 37. Breezy, with a north wind 17 to 22 mph decreasing to 11 to 16 mph after midnight. Winds could gust as high as 37 mph.
Monday
Mostly sunny, with a high near 56. North wind around 10 mph.
Monday Night
Mostly cloudy, with a low around 39. Northeast wind around 6 mph.
Tuesday
Mostly sunny, with a high near 66.
Tuesday Night
Mostly cloudy, with a low around 47.
Wednesday
Partly sunny, with a high near 77.
Wednesday Night
A 20 percent chance of rain and thunderstorms. Partly cloudy, with a low around 61.
Thursday
A 20 percent chance of rain and thunderstorms after 1pm. Sunny, with a high near 89.
Thursday Night
A 50 percent chance of rain and thunderstorms. Mostly cloudy, with a low around 43.
Friday
A 40 percent chance of rain. Mostly cloudy, with a high near 54.
Friday Night
A 20 percent chance of rain. Partly cloudy, with a low around 34.
Saturday
Mostly sunny, with a high near 58.
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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:
1:26 am CDT Mar 22, 2026
Forecast Valid:
2am CDT Mar 22, 2026-6pm CDT Mar 28, 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