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

St. Louis Regional Airport (KALN)

Lat: 38.89°NLon: 90.03°WElev: 518ft.

Fair

77°F

25°C

Humidity 89%
Wind Speed SW 8 mph
Barometer 30.03 in
Dewpoint 73°F (23°C)
Visibility 10.00 mi
Heat Index78°F (26°C)
Last update 18 Jul 6:50 am CDT
Extended Forecast for

Dorchester IL

  • Today

    Today: A 20 percent chance of showers and thunderstorms after 4pm. Increasing clouds, with a high near 90. West wind 6 to 11 mph.

    High: 90 °F

    Sunny then
    Slight Chance
    T-storms

  • Tonight

    Tonight: A 30 percent chance of showers and thunderstorms, mainly before 11pm. Partly cloudy, with a low around 72. West wind 5 to 8 mph becoming calm in the evening.

    Low: 72 °F

    Chance
    T-storms

  • Sunday

    Sunday: A 40 percent chance of showers and thunderstorms, mainly after 2pm. Partly sunny, with a high near 87. Calm wind becoming northeast around 5 mph in the afternoon.

    High: 87 °F

    Mostly Sunny
    then Chance
    Showers

  • Sunday Night

    Sunday Night: Partly cloudy, with a low around 68. East wind around 5 mph becoming calm in the evening.

    Low: 68 °F

    Partly Cloudy

  • Monday

    Monday: Sunny, with a high near 92. Calm wind becoming southwest around 5 mph in the afternoon.

    High: 92 °F

    Sunny

  • Monday Night

    Monday Night: A 20 percent chance of showers and thunderstorms after 1am. Mostly clear, with a low around 74.

    Low: 74 °F

    Mostly Clear
    then Slight
    Chance
    T-storms

  • Tuesday

    Tuesday: Sunny, with a high near 91.

    High: 91 °F

    Sunny

  • Tuesday Night

    Tuesday Night: Mostly clear, with a low around 65.

    Low: 65 °F

    Mostly Clear

  • Wednesday

    Wednesday: Sunny, with a high near 82.

    High: 82 °F

    Sunny

Detailed Forecast

Today
A 20 percent chance of showers and thunderstorms after 4pm. Increasing clouds, with a high near 90. West wind 6 to 11 mph.
Tonight
A 30 percent chance of showers and thunderstorms, mainly before 11pm. Partly cloudy, with a low around 72. West wind 5 to 8 mph becoming calm in the evening.
Sunday
A 40 percent chance of showers and thunderstorms, mainly after 2pm. Partly sunny, with a high near 87. Calm wind becoming northeast around 5 mph in the afternoon.
Sunday Night
Partly cloudy, with a low around 68. East wind around 5 mph becoming calm in the evening.
Monday
Sunny, with a high near 92. Calm wind becoming southwest around 5 mph in the afternoon.
Monday Night
A 20 percent chance of showers and thunderstorms after 1am. Mostly clear, with a low around 74.
Tuesday
Sunny, with a high near 91.
Tuesday Night
Mostly clear, with a low around 65.
Wednesday
Sunny, with a high near 82.
Wednesday Night
Partly cloudy, with a low around 61.
Thursday
Mostly sunny, with a high near 81.
Thursday Night
A 20 percent chance of showers. Partly cloudy, with a low around 62.
Friday
A 20 percent chance of showers. Mostly sunny, with a high near 83.
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Forecast Area
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ABOUT THIS FORECAST

 
Point Forecast:
Dorchester IL
 39.08°N 89.9°W (Elev. 659 ft)
Last Update:
5:56 am CDT Jul 18, 2026
Forecast Valid:
7am CDT Jul 18, 2026-6pm CDT Jul 24, 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