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

Hazardous Weather Conditions

Current conditions at

St. Louis Regional Airport (KALN)

Lat: 38.89°NLon: 90.03°WElev: 518ft.

Fog/Mist

76°F

24°C

Humidity 95%
Wind Speed Calm
Barometer 30.02 in
Dewpoint 74°F (23°C)
Visibility 5.00 mi
Heat Index75°F (24°C)
Last update 18 Aug 1:55 am CDT
Extended Forecast for

Grantfork IL

Heat Advisory August 18, 02:19am until August 18, 08:00pm
Click here for hazard details and duration
Heat Advisory
  •  
    Heat Advisory August 18, 02:19am until August 18, 08:00pm

    NOW until 8:00pm Mon

    Heat Advisory

  • Overnight

    Low: 76 °F

    Partly Cloudy

  • Monday

    Monday: Sunny, with a high near 92. Heat index values as high as 103. South wind 3 to 7 mph.

    High: 92 °F

    Sunny

  • Monday Night

    Monday Night: Mostly clear, with a low around 73. Light southeast wind.

    Low: 73 °F

    Mostly Clear

  • Tuesday

    Tuesday: A 40 percent chance of showers and thunderstorms, mainly after 7am. Mostly sunny, with a high near 91. Heat index values as high as 102. Calm wind becoming west around 5 mph in the afternoon.

    High: 91 °F

    Chance
    Showers then
    Chance
    T-storms

  • Tuesday Night

    Tuesday Night: A chance of showers and thunderstorms before 1am, then a chance of showers between 1am and 4am, then a chance of showers and thunderstorms after 4am. Partly cloudy, with a low around 72. Light north wind. Chance of precipitation is 30%.

    Low: 72 °F

    Chance
    T-storms

  • Wednesday

    Wednesday: A 20 percent chance of showers and thunderstorms. Mostly sunny, with a high near 86.

    High: 86 °F

    Slight Chance
    T-storms

  • Wednesday Night

    Wednesday Night: Partly cloudy, with a low around 64.

    Low: 64 °F

    Partly Cloudy

  • Thursday

    Thursday: Sunny, with a high near 85.

    High: 85 °F

    Sunny

Detailed Forecast

Overnight
Partly cloudy, with a low around 76. Light southeast wind.
Monday
Sunny, with a high near 92. Heat index values as high as 103. South wind 3 to 7 mph.
Monday Night
Mostly clear, with a low around 73. Light southeast wind.
Tuesday
A 40 percent chance of showers and thunderstorms, mainly after 7am. Mostly sunny, with a high near 91. Heat index values as high as 102. Calm wind becoming west around 5 mph in the afternoon.
Tuesday Night
A chance of showers and thunderstorms before 1am, then a chance of showers between 1am and 4am, then a chance of showers and thunderstorms after 4am. Partly cloudy, with a low around 72. Light north wind. Chance of precipitation is 30%.
Wednesday
A 20 percent chance of showers and thunderstorms. Mostly sunny, with a high near 86.
Wednesday Night
Partly cloudy, with a low around 64.
Thursday
Sunny, with a high near 85.
Thursday Night
Mostly clear, with a low around 64.
Friday
Sunny, with a high near 86.
Friday Night
Mostly clear, with a low around 65.
Saturday
Sunny, with a high near 86.
Saturday Night
Mostly clear, with a low around 61.
Sunday
Sunny, with a high near 81.
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Forecast Area
Tiles ©ESRI

ABOUT THIS FORECAST

 
Point Forecast:
Grantfork IL
 38.82°N 89.65°W (Elev. 577 ft)
Last Update:
2:16 am CDT Aug 18, 2025
Forecast Valid:
2am CDT Aug 18, 2025-6pm CDT Aug 24, 2025
 
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