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

Hazardous Weather Conditions

Current conditions at

Decatur Airport (KDEC)

Lat: 39.83°NLon: 88.87°WElev: 670ft.

Fair

2°F

-17°C

Humidity 83%
Wind Speed Calm
Barometer 30.13 in (1021.7 mb)
Dewpoint -2°F (-19°C)
Visibility 10.00 mi
Last update 5 Dec 3:54 am CST
Extended Forecast for

Harristown IL

  • Today

    Today: Patchy freezing fog before 9am. Partly sunny, then gradually becoming sunny, with a high near 30. Wind chill values between -3 and 7. South wind 5 to 10 mph, with gusts as high as 18 mph.

    High: 30 °F

    Patchy
    Freezing Fog
    then Sunny

  • Tonight

    Tonight: Increasing clouds, with a low around 23. South wind 7 to 11 mph becoming west northwest after midnight. Winds could gust as high as 17 mph.

    Low: 23 °F

    Increasing
    Clouds

  • Saturday

    Saturday: Mostly cloudy, with a high near 32. West northwest wind 5 to 7 mph becoming light and variable.

    High: 32 °F

    Mostly Cloudy

  • Saturday Night

    Saturday Night: Snow likely after midnight. Cloudy, with a low around 23. East southeast wind 5 to 9 mph. Chance of precipitation is 60%. New snow accumulation of less than one inch possible.

    Low: 23 °F

    Mostly Cloudy
    then Snow
    Likely

  • Sunday

    Sunday: Snow likely before noon. Mostly cloudy, with a high near 31. East southeast wind 9 to 14 mph becoming north in the afternoon. Winds could gust as high as 20 mph. Chance of precipitation is 60%. New snow accumulation of less than one inch possible.

    High: 31 °F

    Snow Likely
    then Mostly
    Cloudy

  • Sunday Night

    Sunday Night: Mostly cloudy, with a low around 4. North wind 5 to 11 mph, with gusts as high as 16 mph.

    Low: 4 °F

    Mostly Cloudy

  • Monday

    Monday: Mostly sunny, with a high near 24. Light and variable wind becoming south 5 to 7 mph in the afternoon.

    High: 24 °F

    Mostly Sunny

  • Monday Night

    Monday Night: Mostly cloudy, with a low around 15.

    Low: 15 °F

    Mostly Cloudy

  • Tuesday

    Tuesday: Partly sunny, with a high near 36.

    High: 36 °F

    Partly Sunny

Detailed Forecast

Today
Patchy freezing fog before 9am. Partly sunny, then gradually becoming sunny, with a high near 30. Wind chill values between -3 and 7. South wind 5 to 10 mph, with gusts as high as 18 mph.
Tonight
Increasing clouds, with a low around 23. South wind 7 to 11 mph becoming west northwest after midnight. Winds could gust as high as 17 mph.
Saturday
Mostly cloudy, with a high near 32. West northwest wind 5 to 7 mph becoming light and variable.
Saturday Night
Snow likely after midnight. Cloudy, with a low around 23. East southeast wind 5 to 9 mph. Chance of precipitation is 60%. New snow accumulation of less than one inch possible.
Sunday
Snow likely before noon. Mostly cloudy, with a high near 31. East southeast wind 9 to 14 mph becoming north in the afternoon. Winds could gust as high as 20 mph. Chance of precipitation is 60%. New snow accumulation of less than one inch possible.
Sunday Night
Mostly cloudy, with a low around 4. North wind 5 to 11 mph, with gusts as high as 16 mph.
Monday
Mostly sunny, with a high near 24. Light and variable wind becoming south 5 to 7 mph in the afternoon.
Monday Night
Mostly cloudy, with a low around 15.
Tuesday
Partly sunny, with a high near 36.
Tuesday Night
A 30 percent chance of rain after midnight. Mostly cloudy, with a low around 30.
Wednesday
A chance of rain. Mostly cloudy, with a high near 38.
Wednesday Night
Mostly cloudy, with a low around 15.
Thursday
Partly sunny, with a high near 27.
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Forecast Area
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ABOUT THIS FORECAST

 
Point Forecast:
Harristown IL
 39.84°N 89.06°W (Elev. 699 ft)
Last Update:
3:36 am CST Dec 5, 2025
Forecast Valid:
4am CST Dec 5, 2025-6pm CST Dec 11, 2025
 
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Additional Resources

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High Temperature

National Digital Forecast Database Weather Element Forecast

Chance of Precipitation