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

55°F

13°C

Humidity 38%
Wind Speed SE 9 mph
Barometer 30.15 in (1021.1 mb)
Dewpoint 30°F (-1°C)
Visibility 10.00 mi
Wind Chill53°F (12°C)
Last update 24 Mar 10:53 pm CDT
Extended Forecast for

Granite City IL

  • Overnight

    Overnight: Mostly cloudy, with a low around 43. Southeast wind 3 to 6 mph.

    Low: 43 °F

    Mostly Cloudy

  • Wednesday

    Wednesday: Mostly sunny, with a high near 79. Light and variable wind becoming south 6 to 11 mph in the morning.

    High: 79 °F

    Mostly Sunny

  • Wednesday Night

    Wednesday Night: Mostly cloudy, then gradually becoming clear, with a low around 64. South wind around 10 mph, with gusts as high as 20 mph.

    Low: 64 °F

    Decreasing
    Clouds

  • Thursday

    Thursday: Sunny, with a high near 91. Southwest wind 9 to 14 mph, with gusts as high as 24 mph.

    High: 91 °F

    Sunny

  • Thursday Night

    Thursday Night: Rain, mainly after 1am. Low around 44. Southwest wind 10 to 16 mph becoming north after midnight. Winds could gust as high as 25 mph. Chance of precipitation is 90%.

    Low: 44 °F

    Chance Rain
    then Rain

  • Friday

    Friday: A 40 percent chance of rain before 1pm. Partly sunny, with a high near 53.

    High: 53 °F

    Chance Rain

  • Friday Night

    Friday Night: Mostly clear, with a low around 32.

    Low: 32 °F

    Mostly Clear

  • Saturday

    Saturday: Sunny, with a high near 59.

    High: 59 °F

    Sunny

  • Saturday Night

    Saturday Night: Partly cloudy, with a low around 41.

    Low: 41 °F

    Partly Cloudy

Detailed Forecast

Overnight
Mostly cloudy, with a low around 43. Southeast wind 3 to 6 mph.
Wednesday
Mostly sunny, with a high near 79. Light and variable wind becoming south 6 to 11 mph in the morning.
Wednesday Night
Mostly cloudy, then gradually becoming clear, with a low around 64. South wind around 10 mph, with gusts as high as 20 mph.
Thursday
Sunny, with a high near 91. Southwest wind 9 to 14 mph, with gusts as high as 24 mph.
Thursday Night
Rain, mainly after 1am. Low around 44. Southwest wind 10 to 16 mph becoming north after midnight. Winds could gust as high as 25 mph. Chance of precipitation is 90%.
Friday
A 40 percent chance of rain before 1pm. Partly sunny, with a high near 53.
Friday Night
Mostly clear, with a low around 32.
Saturday
Sunny, with a high near 59.
Saturday Night
Partly cloudy, with a low around 41.
Sunday
Partly sunny, with a high near 65.
Sunday Night
Mostly cloudy, with a low around 50.
Monday
Mostly sunny, with a high near 80.
Monday Night
A 30 percent chance of rain. Mostly cloudy, with a low around 59.
Tuesday
A 40 percent chance of rain and thunderstorms. Partly sunny, with a high near 78.
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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:
12:06 am CDT Mar 25, 2026
Forecast Valid:
12am CDT Mar 25, 2026-6pm CDT Mar 31, 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