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

Decatur Airport (KDEC)

Lat: 39.83°NLon: 88.87°WElev: 670ft.

Fair

38°F

3°C

Humidity 68%
Wind Speed S 14 mph
Barometer 29.91 in (1013.0 mb)
Dewpoint 28°F (-2°C)
Visibility 10.00 mi
Wind Chill30°F (-1°C)
Last update 13 Jan 3:54 am CST
Extended Forecast for

Harristown IL

  • Today

    Today: Mostly cloudy, with a high near 53. West wind 11 to 17 mph, with gusts as high as 29 mph.

    High: 53 °F

    Mostly Cloudy

  • Tonight

    Tonight: Mostly cloudy, with a low around 32. West wind 9 to 15 mph, with gusts as high as 22 mph.

    Low: 32 °F

    Mostly Cloudy

  • Wednesday

    Wednesday: A chance of flurries. Partly sunny, with a temperature falling to around 26 by 5pm. Breezy, with a north northwest wind 16 to 23 mph, with gusts as high as 34 mph.

    High: 34 °F⇓

    Chance
    Flurries and
    Breezy

  • Wednesday Night

    Wednesday Night: Mostly clear, with a low around 14. Wind chill values between 4 and 9. North northwest wind 10 to 16 mph, with gusts as high as 28 mph.

    Low: 14 °F

    Mostly Clear

  • Thursday

    Thursday: Sunny, with a high near 27. North northwest wind around 10 mph becoming south southwest in the afternoon. Winds could gust as high as 16 mph.

    High: 27 °F

    Sunny

  • Thursday Night

    Thursday Night: A 50 percent chance of snow showers. Mostly cloudy, with a low around 23. South southwest wind 9 to 17 mph, with gusts as high as 24 mph.

    Low: 23 °F

    Chance Snow
    Showers

  • Friday

    Friday: A 30 percent chance of snow showers after noon. Mostly cloudy, with a high near 38. Breezy, with a west wind 17 to 21 mph, with gusts as high as 29 mph.

    High: 38 °F

    Breezy.
    Mostly Cloudy
    then Chance
    Snow Showers

  • Friday Night

    Friday Night: Mostly cloudy, with a low around 16.

    Low: 16 °F

    Mostly Cloudy

  • Saturday

    Saturday: Mostly cloudy, with a high near 24.

    High: 24 °F

    Mostly Cloudy

Detailed Forecast

Today
Mostly cloudy, with a high near 53. West wind 11 to 17 mph, with gusts as high as 29 mph.
Tonight
Mostly cloudy, with a low around 32. West wind 9 to 15 mph, with gusts as high as 22 mph.
Wednesday
A chance of flurries. Partly sunny, with a temperature falling to around 26 by 5pm. Breezy, with a north northwest wind 16 to 23 mph, with gusts as high as 34 mph.
Wednesday Night
Mostly clear, with a low around 14. Wind chill values between 4 and 9. North northwest wind 10 to 16 mph, with gusts as high as 28 mph.
Thursday
Sunny, with a high near 27. North northwest wind around 10 mph becoming south southwest in the afternoon. Winds could gust as high as 16 mph.
Thursday Night
A 50 percent chance of snow showers. Mostly cloudy, with a low around 23. South southwest wind 9 to 17 mph, with gusts as high as 24 mph.
Friday
A 30 percent chance of snow showers after noon. Mostly cloudy, with a high near 38. Breezy, with a west wind 17 to 21 mph, with gusts as high as 29 mph.
Friday Night
Mostly cloudy, with a low around 16.
Saturday
Mostly cloudy, with a high near 24.
Saturday Night
Mostly cloudy, with a low around 6.
Sunday
Partly sunny, with a high near 19.
Sunday Night
Partly cloudy, with a low around 8.
M.L.King Day
Mostly sunny, with a high near 25.
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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:
4:16 am CST Jan 13, 2026
Forecast Valid:
4am CST Jan 13, 2026-6pm CST Jan 19, 2026
 
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Additional Resources

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High Temperature

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Chance of Precipitation