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

Heat Builds in the West; Extremely Critical Fire Weather in the Northwest

A heat wave over the Southwest will intensify this week, peaking and expanding into the Intermountain West and northern High Plains this weekend. Critical to extremely critical fire weather conditions are forecast from the Northwest and the northern Great Basin this weekend. Particularly Dangerous Situation Red Flag Warnings have been issued. Read More >

Current conditions at

St. Louis Regional Airport (KALN)

Lat: 38.89°NLon: 90.03°WElev: 518ft.

Overcast

73°F

23°C

Humidity 78%
Wind Speed N 12 mph
Barometer 29.88 in
Dewpoint 66°F (19°C)
Visibility 10.00 mi
Last update 2 Aug 11:45 am CDT
Extended Forecast for

Gillespie IL

  • This Afternoon

    This Afternoon: Mostly sunny, with a high near 80. North wind around 14 mph.

    High: 80 °F

    Mostly Sunny

  • Tonight

    Tonight: Mostly clear, with a low around 60. North wind 5 to 8 mph becoming calm in the evening.

    Low: 60 °F

    Mostly Clear

  • Monday

    Monday: Sunny, with a high near 83. Light northeast wind.

    High: 83 °F

    Sunny

  • Monday Night

    Monday Night: Clear, with a low around 61. Calm wind.

    Low: 61 °F

    Clear

  • Tuesday

    Tuesday: Sunny, with a high near 86. Light south wind.

    High: 86 °F

    Sunny

  • Tuesday Night

    Tuesday Night: Mostly clear, with a low around 62.

    Low: 62 °F

    Mostly Clear

  • Wednesday

    Wednesday: Sunny, with a high near 87.

    High: 87 °F

    Sunny

  • Wednesday Night

    Wednesday Night: A 40 percent chance of showers and thunderstorms, mainly after 1am. Partly cloudy, with a low around 66.

    Low: 66 °F

    Chance
    T-storms

  • Thursday

    Thursday: A 50 percent chance of showers and thunderstorms, mainly before 1pm. Partly sunny, with a high near 84.

    High: 84 °F

    Chance
    T-storms

Detailed Forecast

This Afternoon
Mostly sunny, with a high near 80. North wind around 14 mph.
Tonight
Mostly clear, with a low around 60. North wind 5 to 8 mph becoming calm in the evening.
Monday
Sunny, with a high near 83. Light northeast wind.
Monday Night
Clear, with a low around 61. Calm wind.
Tuesday
Sunny, with a high near 86. Light south wind.
Tuesday Night
Mostly clear, with a low around 62.
Wednesday
Sunny, with a high near 87.
Wednesday Night
A 40 percent chance of showers and thunderstorms, mainly after 1am. Partly cloudy, with a low around 66.
Thursday
A 50 percent chance of showers and thunderstorms, mainly before 1pm. Partly sunny, with a high near 84.
Thursday Night
A 30 percent chance of showers and thunderstorms, mainly after 1am. Mostly cloudy, with a low around 66.
Friday
A 30 percent chance of showers and thunderstorms. Partly sunny, with a high near 85.
Friday Night
A 20 percent chance of showers and thunderstorms. Partly cloudy, with a low around 67.
Saturday
A 20 percent chance of showers and thunderstorms. Mostly sunny, with a high near 87.
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Forecast Area
Tiles ©ESRI

ABOUT THIS FORECAST

 
Point Forecast:
Gillespie IL
 39.12°N 89.81°W (Elev. 653 ft)
Last Update:
1:11 pm CDT Aug 2, 2026
Forecast Valid:
1pm CDT Aug 2, 2026-6pm CDT Aug 8, 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