National Oceanic and Atmospheric Administration National Weather Service United States Department of Commerce

Dangerous Heat and Possible Flooding

Dangerous heat will persist across the Southwest U.S. through Saturday with daytime highs of 110-115°F. Extreme Heat Warnings remain in effect. Dangerous heat will build across the southern Plains again beginning this weekend. Heavy to excessive rain over the Carolinas Friday may lead to isolated areas of flash flooding. Read More >

Current conditions at

St. Louis Downtown Airport (KCPS)

Lat: 38.56°NLon: 90.15°WElev: 410ft.

Fair

63°F

17°C

Humidity 93%
Wind Speed Calm
Barometer 30.08 in (1018.2 mb)
Dewpoint 61°F (16°C)
Visibility 10.00 mi
Last update 28 Aug 2:53 am CDT
Extended Forecast for

Granite City IL

  • Overnight

    Overnight: Patchy fog after 5am. Otherwise, clear, with a low around 63. Calm wind.

    Low: 63 °F

    Patchy Fog

  • Friday

    Friday: Patchy fog before 8am. Otherwise, sunny, with a high near 89. Calm wind becoming north around 5 mph in the afternoon.

    High: 89 °F

    Patchy Fog
    then Sunny

  • Friday Night

    Friday Night: Mostly clear, with a low around 65. Light east wind.

    Low: 65 °F

    Mostly Clear

  • Saturday

    Saturday: Mostly sunny, with a high near 90. Calm wind becoming south 5 to 7 mph in the morning.

    High: 90 °F

    Mostly Sunny

  • Saturday Night

    Saturday Night: Partly cloudy, with a low around 70. South wind around 7 mph.

    Low: 70 °F

    Partly Cloudy

  • Sunday

    Sunday: Sunny, with a high near 96.

    High: 96 °F

    Sunny

  • Sunday Night

    Sunday Night: Mostly clear, with a low around 75.

    Low: 75 °F

    Mostly Clear

  • Monday

    Monday: Sunny and hot, with a high near 100.

    High: 100 °F

    Hot

  • Monday Night

    Monday Night: Mostly clear, with a low around 78.

    Low: 78 °F

    Mostly Clear

Detailed Forecast

Overnight
Patchy fog after 5am. Otherwise, clear, with a low around 63. Calm wind.
Friday
Patchy fog before 8am. Otherwise, sunny, with a high near 89. Calm wind becoming north around 5 mph in the afternoon.
Friday Night
Mostly clear, with a low around 65. Light east wind.
Saturday
Mostly sunny, with a high near 90. Calm wind becoming south 5 to 7 mph in the morning.
Saturday Night
Partly cloudy, with a low around 70. South wind around 7 mph.
Sunday
Sunny, with a high near 96.
Sunday Night
Mostly clear, with a low around 75.
Monday
Sunny and hot, with a high near 100.
Monday Night
Mostly clear, with a low around 78.
Tuesday
Sunny and hot, with a high near 100.
Tuesday Night
Mostly clear, with a low around 80.
Wednesday
Sunny and hot, with a high near 100.
Wednesday Night
Mostly clear, with a low around 80.
Thursday
A 20 percent chance of showers. Sunny and hot, with a high near 101.
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Forecast Area
Tiles ©ESRI

ABOUT THIS FORECAST

 
Point Forecast:
Granite City IL
 38.71°N 90.14°W (Elev. 410 ft)
Last Update:
3:31 am CDT Aug 28, 2026
Forecast Valid:
3am CDT Aug 28, 2026-6pm CDT Sep 3, 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