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.

Mostly Cloudy

45°F

7°C

Humidity 46%
Wind Speed S 14 mph
Barometer 30.29 in (1025.9 mb)
Dewpoint 25°F (-4°C)
Visibility 10.00 mi
Wind Chill39°F (4°C)
Last update 29 Mar 3:54 am CDT
Extended Forecast for

2 Miles ENE Harristown IL

  • Today

    Today: Mostly sunny, with a high near 66. South southwest wind 9 to 17 mph, with gusts as high as 25 mph.

    High: 66 °F

    Mostly Sunny

  • Tonight

    Tonight: Mostly cloudy, with a low around 55. South wind around 14 mph, with gusts as high as 25 mph.

    Low: 55 °F

    Mostly Cloudy

  • Monday

    Monday: Mostly sunny, with a high near 80. Breezy, with a south southwest wind 14 to 21 mph, with gusts as high as 30 mph.

    High: 80 °F

    Mostly Sunny
    then Mostly
    Sunny and
    Breezy

  • Monday Night

    Monday Night: Partly cloudy, with a low around 63. Breezy, with a south wind 18 to 21 mph, with gusts as high as 30 mph.

    Low: 63 °F

    Partly Cloudy
    and Breezy

  • Tuesday

    Tuesday: A chance of rain, then rain likely and possibly a thunderstorm after 1pm. Mostly cloudy, with a high near 81. Breezy, with a southwest wind 20 to 25 mph, with gusts as high as 38 mph. Chance of precipitation is 60%. New rainfall amounts between a tenth and quarter of an inch, except higher amounts possible in thunderstorms.

    High: 81 °F

    Breezy.
    Chance Rain
    then Rain
    Likely

  • Tuesday Night

    Tuesday Night: Rain and possibly a thunderstorm. Low around 45. West southwest wind 15 to 18 mph becoming north after midnight. Winds could gust as high as 28 mph. Chance of precipitation is 80%. New rainfall amounts between three quarters and one inch possible.

    Low: 45 °F

    Rain

  • Wednesday

    Wednesday: A 40 percent chance of rain. Mostly cloudy, with a high near 53. Northeast wind around 17 mph, with gusts as high as 25 mph.

    High: 53 °F

    Chance Rain

  • Wednesday Night

    Wednesday Night: Rain likely, mainly after 1am. Cloudy, with a low around 41. Chance of precipitation is 60%.

    Low: 41 °F

    Rain Likely

  • Thursday

    Thursday: Rain likely. Cloudy, with a high near 60. Chance of precipitation is 70%.

    High: 60 °F

    Rain Likely

Detailed Forecast

Today
Mostly sunny, with a high near 66. South southwest wind 9 to 17 mph, with gusts as high as 25 mph.
Tonight
Mostly cloudy, with a low around 55. South wind around 14 mph, with gusts as high as 25 mph.
Monday
Mostly sunny, with a high near 80. Breezy, with a south southwest wind 14 to 21 mph, with gusts as high as 30 mph.
Monday Night
Partly cloudy, with a low around 63. Breezy, with a south wind 18 to 21 mph, with gusts as high as 30 mph.
Tuesday
A chance of rain, then rain likely and possibly a thunderstorm after 1pm. Mostly cloudy, with a high near 81. Breezy, with a southwest wind 20 to 25 mph, with gusts as high as 38 mph. Chance of precipitation is 60%. New rainfall amounts between a tenth and quarter of an inch, except higher amounts possible in thunderstorms.
Tuesday Night
Rain and possibly a thunderstorm. Low around 45. West southwest wind 15 to 18 mph becoming north after midnight. Winds could gust as high as 28 mph. Chance of precipitation is 80%. New rainfall amounts between three quarters and one inch possible.
Wednesday
A 40 percent chance of rain. Mostly cloudy, with a high near 53. Northeast wind around 17 mph, with gusts as high as 25 mph.
Wednesday Night
Rain likely, mainly after 1am. Cloudy, with a low around 41. Chance of precipitation is 60%.
Thursday
Rain likely. Cloudy, with a high near 60. Chance of precipitation is 70%.
Thursday Night
Rain likely, mainly before 1am. Mostly cloudy, with a low around 43. Chance of precipitation is 60%.
Friday
A chance of rain. Mostly cloudy, with a high near 70.
Friday Night
Rain likely. Mostly cloudy, with a low around 53.
Saturday
Rain likely. Mostly cloudy, with a high near 68. Breezy.
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Forecast Area
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ABOUT THIS FORECAST

 
Point Forecast:
2 Miles ENE Harristown IL
 39.84°N 89.03°W (Elev. 666 ft)
Last Update:
2:00 am CDT Mar 29, 2026
Forecast Valid:
4am CDT Mar 29, 2026-6pm CDT Apr 4, 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