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.

Fair

68°F

20°C

Humidity 77%
Wind Speed Calm
Barometer 29.96 in
Dewpoint 61°F (16°C)
Visibility 10.00 mi
Last update 20 Jun 11:55 pm CDT
Extended Forecast for

Gillespie IL

Flood Watch June 21, 07:00am until June 22, 01:00am
Click here for hazard details and duration
Flood Watch

  • Overnight

    Overnight: Mostly cloudy, with a low around 66. Calm wind becoming east around 6 mph.

    Low: 66 °F

    Mostly Cloudy

  • Sunday

    Sunday: Showers and thunderstorms. High near 80. East wind 9 to 16 mph becoming southwest in the afternoon. Winds could gust as high as 25 mph. Chance of precipitation is 90%.

    High: 80 °F

    Chance
    T-storms then
    T-storms

  • Sunday Night

    Sunday Night: Showers and thunderstorms, mainly before midnight. Low around 60. Southwest wind 7 to 13 mph becoming northwest after midnight. Winds could gust as high as 20 mph. Chance of precipitation is 90%.

    Low: 60 °F

    T-storms then
    Slight Chance
    T-storms

  • Monday

    Monday: A slight chance of showers and thunderstorms between 7am and 9am. Mostly cloudy, with a high near 74. North wind around 11 mph. Chance of precipitation is 20%.

    High: 74 °F

    Slight Chance
    T-storms then
    Partly Sunny

  • Monday Night

    Monday Night: Partly cloudy, with a low around 57. North wind 5 to 8 mph becoming calm in the evening.

    Low: 57 °F

    Partly Cloudy

  • Tuesday

    Tuesday: Mostly sunny, with a high near 78.

    High: 78 °F

    Mostly Sunny

  • Tuesday Night

    Tuesday Night: Mostly clear, with a low around 59.

    Low: 59 °F

    Mostly Clear

  • Wednesday

    Wednesday: Mostly sunny, with a high near 81.

    High: 81 °F

    Mostly Sunny

  • Wednesday Night

    Wednesday Night: Partly cloudy, with a low around 59.

    Low: 59 °F

    Partly Cloudy

Detailed Forecast

Overnight
Mostly cloudy, with a low around 66. Calm wind becoming east around 6 mph.
Sunday
Showers and thunderstorms. High near 80. East wind 9 to 16 mph becoming southwest in the afternoon. Winds could gust as high as 25 mph. Chance of precipitation is 90%.
Sunday Night
Showers and thunderstorms, mainly before midnight. Low around 60. Southwest wind 7 to 13 mph becoming northwest after midnight. Winds could gust as high as 20 mph. Chance of precipitation is 90%.
Monday
A slight chance of showers and thunderstorms between 7am and 9am. Mostly cloudy, with a high near 74. North wind around 11 mph. Chance of precipitation is 20%.
Monday Night
Partly cloudy, with a low around 57. North wind 5 to 8 mph becoming calm in the evening.
Tuesday
Mostly sunny, with a high near 78.
Tuesday Night
Mostly clear, with a low around 59.
Wednesday
Mostly sunny, with a high near 81.
Wednesday Night
Partly cloudy, with a low around 59.
Thursday
A 20 percent chance of showers and thunderstorms after 1pm. Mostly sunny, with a high near 79.
Thursday Night
A 20 percent chance of showers and thunderstorms. Partly cloudy, with a low around 59.
Friday
A 30 percent chance of showers and thunderstorms. Mostly sunny, with a high near 81.
Friday Night
A 40 percent chance of showers and thunderstorms. Mostly cloudy, with a low around 63.
Saturday
A 40 percent chance of showers and thunderstorms. Partly sunny, with a high near 83.
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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:
11:51 pm CDT Jun 20, 2026
Forecast Valid:
12am CDT Jun 21, 2026-6pm CDT Jun 27, 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