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Hazardous Weather Conditions

Current conditions at

Decatur Airport (KDEC)

Lat: 39.83°NLon: 88.87°WElev: 670ft.

A Few Clouds

77°F

25°C

Humidity 71%
Wind Speed NW 3 mph
Barometer 30.02 in (1016.1 mb)
Dewpoint 67°F (19°C)
Visibility 10.00 mi
Heat Index79°F (26°C)
Last update 14 Oct 2:54 pm CDT
Extended Forecast for

Harristown IL

  • This Afternoon

    This Afternoon: Mostly cloudy, with a high near 78. North wind around 6 mph.

    High: 78 °F

    Mostly Cloudy

  • Tonight

    Tonight: A 20 percent chance of showers after 4am. Mostly cloudy, with a low around 60. East northeast wind 8 to 10 mph, with gusts as high as 16 mph.

    Low: 60 °F

    Mostly Cloudy
    then Slight
    Chance
    Showers

  • Thursday

    Thursday: Showers and thunderstorms likely before 9am, then showers and possibly a thunderstorm between 9am and 1pm, then a chance of showers and thunderstorms after 1pm. High near 76. East wind 7 to 10 mph becoming south in the afternoon. Winds could gust as high as 18 mph. Chance of precipitation is 100%. New rainfall amounts between a quarter and half of an inch possible.

    High: 76 °F

    Showers

  • Thursday Night

    Thursday Night: A chance of showers and thunderstorms before 10pm, then a chance of showers between 10pm and 3am. Mostly cloudy, with a low around 48. Breezy, with a west southwest wind 10 to 15 mph becoming northwest 18 to 23 mph after midnight. Winds could gust as high as 30 mph. Chance of precipitation is 50%.

    Low: 48 °F

    Chance
    T-storms then
    Chance
    Showers and
    Breezy

  • Friday

    Friday: A 30 percent chance of showers after 1pm. Partly sunny, with a high near 56. Breezy, with a northwest wind 22 to 25 mph, with gusts as high as 34 mph.

    High: 56 °F

    Breezy.
    Partly Sunny
    then Chance
    Showers

  • Friday Night

    Friday Night: Mostly cloudy, then gradually becoming clear, with a low around 37. North wind 11 to 17 mph, with gusts as high as 21 mph.

    Low: 37 °F

    Decreasing
    Clouds

  • Saturday

    Saturday: Patchy frost before 8am. Otherwise, sunny, with a high near 59. North wind 5 to 7 mph becoming calm in the afternoon.

    High: 59 °F

    Patchy Frost
    then Sunny

  • Saturday Night

    Saturday Night: Clear, with a low around 36.

    Low: 36 °F

    Clear

  • Sunday

    Sunday: Areas of frost before 7am. Otherwise, sunny, with a high near 66.

    High: 66 °F

    Areas Frost
    then Sunny

Detailed Forecast

This Afternoon
Mostly cloudy, with a high near 78. North wind around 6 mph.
Tonight
A 20 percent chance of showers after 4am. Mostly cloudy, with a low around 60. East northeast wind 8 to 10 mph, with gusts as high as 16 mph.
Thursday
Showers and thunderstorms likely before 9am, then showers and possibly a thunderstorm between 9am and 1pm, then a chance of showers and thunderstorms after 1pm. High near 76. East wind 7 to 10 mph becoming south in the afternoon. Winds could gust as high as 18 mph. Chance of precipitation is 100%. New rainfall amounts between a quarter and half of an inch possible.
Thursday Night
A chance of showers and thunderstorms before 10pm, then a chance of showers between 10pm and 3am. Mostly cloudy, with a low around 48. Breezy, with a west southwest wind 10 to 15 mph becoming northwest 18 to 23 mph after midnight. Winds could gust as high as 30 mph. Chance of precipitation is 50%.
Friday
A 30 percent chance of showers after 1pm. Partly sunny, with a high near 56. Breezy, with a northwest wind 22 to 25 mph, with gusts as high as 34 mph.
Friday Night
Mostly cloudy, then gradually becoming clear, with a low around 37. North wind 11 to 17 mph, with gusts as high as 21 mph.
Saturday
Patchy frost before 8am. Otherwise, sunny, with a high near 59. North wind 5 to 7 mph becoming calm in the afternoon.
Saturday Night
Clear, with a low around 36.
Sunday
Areas of frost before 7am. Otherwise, sunny, with a high near 66.
Sunday Night
Mostly clear, with a low around 40.
Monday
Mostly sunny, with a high near 72.
Monday Night
Partly cloudy, with a low around 43.
Tuesday
Mostly sunny, with a high near 73.
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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 pm CDT Oct 14, 2026
Forecast Valid:
3pm CDT Oct 14, 2026-6pm CDT Oct 20, 2026
 
Forecast Discussion
 
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Additional Resources

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Hourly Weather Forecast

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High Temperature

National Digital Forecast Database Weather Element Forecast

Chance of Precipitation