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

80°F

27°C

Humidity 79%
Wind Speed NE 8 mph
Barometer 29.86 in (1010.7 mb)
Dewpoint 73°F (23°C)
Visibility 10.00 mi
Heat Index84°F (29°C)
Last update 28 Jul 9:53 pm CDT
Extended Forecast for

Granite City IL

  • Tonight

    Tonight: Mostly clear, with a low around 70. Northeast wind 3 to 6 mph.

    Low: 70 °F

    Mostly Clear

  • Wednesday

    Wednesday: Sunny, with a high near 89. Calm wind becoming northeast 5 to 7 mph in the afternoon.

    High: 89 °F

    Sunny

  • Wednesday Night

    Wednesday Night: Mostly clear, with a low around 67. Northeast wind 5 to 7 mph becoming calm in the evening.

    Low: 67 °F

    Mostly Clear

  • Thursday

    Thursday: Sunny, with a high near 88. Calm wind becoming southeast around 6 mph in the morning.

    High: 88 °F

    Sunny

  • Thursday Night

    Thursday Night: Partly cloudy, with a low around 69. Southeast wind 3 to 6 mph.

    Low: 69 °F

    Partly Cloudy

  • Friday

    Friday: Showers likely, with thunderstorms also possible after 1pm. Mostly cloudy, with a high near 86. Chance of precipitation is 60%.

    High: 86 °F

    Showers
    Likely

  • Friday Night

    Friday Night: Showers likely and possibly a thunderstorm before 1am, then a chance of showers and thunderstorms after 1am. Mostly cloudy, with a low around 70. Chance of precipitation is 60%.

    Low: 70 °F

    Showers
    Likely

  • Saturday

    Saturday: A chance of showers, then showers likely and possibly a thunderstorm after 1pm. Mostly cloudy, with a high near 80. Chance of precipitation is 60%.

    High: 80 °F

    Showers
    Likely

  • Saturday Night

    Saturday Night: A chance of showers and thunderstorms before 1am, then a slight chance of showers. Mostly cloudy, with a low around 68. Chance of precipitation is 30%.

    Low: 68 °F

    Chance
    T-storms

Detailed Forecast

Tonight
Mostly clear, with a low around 70. Northeast wind 3 to 6 mph.
Wednesday
Sunny, with a high near 89. Calm wind becoming northeast 5 to 7 mph in the afternoon.
Wednesday Night
Mostly clear, with a low around 67. Northeast wind 5 to 7 mph becoming calm in the evening.
Thursday
Sunny, with a high near 88. Calm wind becoming southeast around 6 mph in the morning.
Thursday Night
Partly cloudy, with a low around 69. Southeast wind 3 to 6 mph.
Friday
Showers likely, with thunderstorms also possible after 1pm. Mostly cloudy, with a high near 86. Chance of precipitation is 60%.
Friday Night
Showers likely and possibly a thunderstorm before 1am, then a chance of showers and thunderstorms after 1am. Mostly cloudy, with a low around 70. Chance of precipitation is 60%.
Saturday
A chance of showers, then showers likely and possibly a thunderstorm after 1pm. Mostly cloudy, with a high near 80. Chance of precipitation is 60%.
Saturday Night
A chance of showers and thunderstorms before 1am, then a slight chance of showers. Mostly cloudy, with a low around 68. Chance of precipitation is 30%.
Sunday
A slight chance of showers, then a chance of showers and thunderstorms after 1pm. Mostly sunny, with a high near 84. Chance of precipitation is 30%.
Sunday Night
Partly cloudy, with a low around 68.
Monday
A 20 percent chance of showers and thunderstorms. Mostly sunny, with a high near 86.
Monday Night
Mostly clear, with a low around 70.
Tuesday
A 20 percent chance of showers and thunderstorms. Mostly sunny, with a high near 89.
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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:
10:31 pm CDT Jul 28, 2026
Forecast Valid:
10pm CDT Jul 28, 2026-6pm CDT Aug 4, 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