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

64°F

18°C

Humidity 75%
Wind Speed NE 8 mph
Barometer 30.27 in (1024.6 mb)
Dewpoint 56°F (13°C)
Visibility 9.00 mi
Last update 14 Oct 9:54 pm CDT
Extended Forecast for

Harristown IL

  • Tonight

    Tonight: Mostly cloudy, with a low around 58. East northeast wind around 8 mph, with gusts as high as 15 mph.

    Low: 58 °F

    Mostly Cloudy

  • Wednesday

    Wednesday: Partly sunny, with a high near 77. Northeast wind 3 to 6 mph.

    High: 77 °F

    Partly Sunny

  • Wednesday Night

    Wednesday Night: Partly cloudy, with a low around 57. East northeast wind around 7 mph.

    Low: 57 °F

    Partly Cloudy

  • Thursday

    Thursday: Sunny, with a high near 78. Southeast wind 8 to 10 mph.

    High: 78 °F

    Sunny

  • Thursday Night

    Thursday Night: Partly cloudy, with a low around 55. Southeast wind around 10 mph, with gusts as high as 15 mph.

    Low: 55 °F

    Partly Cloudy

  • Friday

    Friday: Partly sunny, with a high near 79. South wind 10 to 14 mph, with gusts as high as 18 mph.

    High: 79 °F

    Partly Sunny

  • Friday Night

    Friday Night: A 30 percent chance of showers after 1am. Partly cloudy, with a low around 61. South wind 11 to 13 mph, with gusts as high as 17 mph.

    Low: 61 °F

    Partly Cloudy
    then Chance
    Showers

  • Saturday

    Saturday: Showers likely. Partly sunny, with a high near 74. Chance of precipitation is 70%.

    High: 74 °F

    Showers
    Likely

  • Saturday Night

    Saturday Night: Showers likely, mainly before 1am. Partly cloudy, with a low around 48. Chance of precipitation is 60%.

    Low: 48 °F

    Showers
    Likely

Detailed Forecast

Tonight
Mostly cloudy, with a low around 58. East northeast wind around 8 mph, with gusts as high as 15 mph.
Wednesday
Partly sunny, with a high near 77. Northeast wind 3 to 6 mph.
Wednesday Night
Partly cloudy, with a low around 57. East northeast wind around 7 mph.
Thursday
Sunny, with a high near 78. Southeast wind 8 to 10 mph.
Thursday Night
Partly cloudy, with a low around 55. Southeast wind around 10 mph, with gusts as high as 15 mph.
Friday
Partly sunny, with a high near 79. South wind 10 to 14 mph, with gusts as high as 18 mph.
Friday Night
A 30 percent chance of showers after 1am. Partly cloudy, with a low around 61. South wind 11 to 13 mph, with gusts as high as 17 mph.
Saturday
Showers likely. Partly sunny, with a high near 74. Chance of precipitation is 70%.
Saturday Night
Showers likely, mainly before 1am. Partly cloudy, with a low around 48. Chance of precipitation is 60%.
Sunday
A 30 percent chance of showers before 1pm. Sunny, with a high near 65.
Sunday Night
Mostly clear, with a low around 42.
Monday
Sunny, with a high near 69.
Monday Night
Mostly clear, with a low around 47.
Tuesday
Sunny, with a high near 70.
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Forecast Area
Tiles ©ESRI

ABOUT THIS FORECAST

 
Point Forecast:
Harristown IL
 39.84°N 89.06°W (Elev. 699 ft)
Last Update:
9:22 pm CDT Oct 14, 2025
Forecast Valid:
10pm CDT Oct 14, 2025-6pm CDT Oct 21, 2025
 
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