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Current conditions at

Decatur Airport (KDEC)

Lat: 39.83°NLon: 88.87°WElev: 670ft.

Fair

57°F

14°C

Humidity 62%
Wind Speed SW 5 mph
Barometer 29.99 in (1015.3 mb)
Dewpoint 44°F (7°C)
Visibility 10.00 mi
Last update 6 Oct 9:54 pm CDT
Extended Forecast for

Harristown IL

  • Tonight

    Tonight: Clear, with a low around 50. South wind around 8 mph.

    Low: 50 °F

    Clear

  • Wednesday

    Wednesday: Sunny, with a high near 84. Southwest wind 7 to 11 mph becoming west northwest in the afternoon. Winds could gust as high as 17 mph.

    High: 84 °F

    Sunny

  • Wednesday Night

    Wednesday Night: Mostly clear, with a low around 52. North northwest wind around 6 mph becoming calm in the evening.

    Low: 52 °F

    Mostly Clear

  • Thursday

    Thursday: Sunny, with a high near 77. Light northwest wind becoming north northwest 5 to 9 mph in the morning.

    High: 77 °F

    Sunny

  • Thursday Night

    Thursday Night: Mostly clear, with a low around 49. North wind around 6 mph becoming light and variable.

    Low: 49 °F

    Mostly Clear

  • Friday

    Friday: Sunny, with a high near 80. East wind 6 to 11 mph becoming south in the afternoon. Winds could gust as high as 15 mph.

    High: 80 °F

    Sunny

  • Friday Night

    Friday Night: Mostly clear, with a low around 55. South southeast wind around 10 mph, with gusts as high as 16 mph.

    Low: 55 °F

    Mostly Clear

  • Saturday

    Saturday: Sunny, with a high near 86.

    High: 86 °F

    Sunny

  • Saturday Night

    Saturday Night: Partly cloudy, with a low around 59.

    Low: 59 °F

    Partly Cloudy

Detailed Forecast

Tonight
Clear, with a low around 50. South wind around 8 mph.
Wednesday
Sunny, with a high near 84. Southwest wind 7 to 11 mph becoming west northwest in the afternoon. Winds could gust as high as 17 mph.
Wednesday Night
Mostly clear, with a low around 52. North northwest wind around 6 mph becoming calm in the evening.
Thursday
Sunny, with a high near 77. Light northwest wind becoming north northwest 5 to 9 mph in the morning.
Thursday Night
Mostly clear, with a low around 49. North wind around 6 mph becoming light and variable.
Friday
Sunny, with a high near 80. East wind 6 to 11 mph becoming south in the afternoon. Winds could gust as high as 15 mph.
Friday Night
Mostly clear, with a low around 55. South southeast wind around 10 mph, with gusts as high as 16 mph.
Saturday
Sunny, with a high near 86.
Saturday Night
Partly cloudy, with a low around 59.
Sunday
A 30 percent chance of showers before 1pm. Mostly sunny, with a high near 78.
Sunday Night
Partly cloudy, with a low around 56.
Columbus Day
Mostly sunny, with a high near 81.
Monday Night
Mostly clear, with a low around 57.
Tuesday
Mostly sunny, with a high near 78.
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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:
7:41 pm CDT Oct 6, 2026
Forecast Valid:
10pm CDT Oct 6, 2026-6pm CDT Oct 13, 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