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

Hazardous Weather Conditions

Current conditions at

Decatur Airport (KDEC)

Lat: 39.83°NLon: 88.87°WElev: 670ft.

Fair

60°F

16°C

Humidity 93%
Wind Speed SW 12 mph
Barometer 29.84 in (1010.1 mb)
Dewpoint 58°F (14°C)
Visibility 10.00 mi
Last update 10 Mar 4:54 am CDT
Extended Forecast for

Harristown IL

  • Today

    Today: A 20 percent chance of showers and thunderstorms after 4pm. Mostly sunny, with a high near 77. South southwest wind 11 to 18 mph, with gusts as high as 26 mph.

    High: 77 °F

    Mostly Sunny
    then Slight
    Chance
    T-storms

  • Tonight

    Tonight: Showers and thunderstorms likely, then showers and possibly a thunderstorm after 4am. Low around 53. Breezy, with a south southwest wind 17 to 20 mph, with gusts as high as 32 mph. Chance of precipitation is 90%. New rainfall amounts between a quarter and half of an inch possible.

    Low: 53 °F

    Chance
    T-storms and
    Breezy then
    T-storms

  • Wednesday

    Wednesday: Showers and possibly a thunderstorm before 1pm, then a chance of showers. Temperature falling to around 44 by 5pm. Breezy, with a west southwest wind 18 to 24 mph becoming northwest in the afternoon. Winds could gust as high as 32 mph. Chance of precipitation is 90%. New precipitation amounts between a half and three quarters of an inch possible.

    High: 61 °F⇓

    Breezy.
    T-storms then
    Showers
    Likely

  • Wednesday Night

    Wednesday Night: Mostly cloudy, then gradually becoming clear, with a low around 30. Blustery, with a northwest wind 16 to 21 mph decreasing to 9 to 14 mph after midnight. Winds could gust as high as 29 mph.

    Low: 30 °F

    Mostly Cloudy
    and Blustery
    then Partly
    Cloudy

  • Thursday

    Thursday: Increasing clouds, with a high near 50. Northwest wind 6 to 14 mph becoming southwest in the afternoon. Winds could gust as high as 20 mph.

    High: 50 °F

    Increasing
    Clouds

  • Thursday Night

    Thursday Night: Mostly cloudy, with a low around 42. Breezy, with a south wind 13 to 18 mph increasing to 21 to 26 mph after midnight. Winds could gust as high as 36 mph.

    Low: 42 °F

    Mostly Cloudy
    and Breezy

  • Friday

    Friday: Mostly cloudy, with a high near 56. Breezy, with a southwest wind 17 to 23 mph becoming west northwest in the afternoon. Winds could gust as high as 32 mph.

    High: 56 °F

    Mostly Cloudy
    and Breezy

  • Friday Night

    Friday Night: Mostly cloudy, with a low around 35.

    Low: 35 °F

    Mostly Cloudy

  • Saturday

    Saturday: Mostly cloudy, with a high near 60. Breezy.

    High: 60 °F

    Mostly Cloudy
    then Partly
    Sunny and
    Breezy

Detailed Forecast

Today
A 20 percent chance of showers and thunderstorms after 4pm. Mostly sunny, with a high near 77. South southwest wind 11 to 18 mph, with gusts as high as 26 mph.
Tonight
Showers and thunderstorms likely, then showers and possibly a thunderstorm after 4am. Low around 53. Breezy, with a south southwest wind 17 to 20 mph, with gusts as high as 32 mph. Chance of precipitation is 90%. New rainfall amounts between a quarter and half of an inch possible.
Wednesday
Showers and possibly a thunderstorm before 1pm, then a chance of showers. Temperature falling to around 44 by 5pm. Breezy, with a west southwest wind 18 to 24 mph becoming northwest in the afternoon. Winds could gust as high as 32 mph. Chance of precipitation is 90%. New precipitation amounts between a half and three quarters of an inch possible.
Wednesday Night
Mostly cloudy, then gradually becoming clear, with a low around 30. Blustery, with a northwest wind 16 to 21 mph decreasing to 9 to 14 mph after midnight. Winds could gust as high as 29 mph.
Thursday
Increasing clouds, with a high near 50. Northwest wind 6 to 14 mph becoming southwest in the afternoon. Winds could gust as high as 20 mph.
Thursday Night
Mostly cloudy, with a low around 42. Breezy, with a south wind 13 to 18 mph increasing to 21 to 26 mph after midnight. Winds could gust as high as 36 mph.
Friday
Mostly cloudy, with a high near 56. Breezy, with a southwest wind 17 to 23 mph becoming west northwest in the afternoon. Winds could gust as high as 32 mph.
Friday Night
Mostly cloudy, with a low around 35.
Saturday
Mostly cloudy, with a high near 60. Breezy.
Saturday Night
A 30 percent chance of rain after 1am. Mostly cloudy, with a low around 45. Breezy.
Sunday
Rain. Mostly cloudy, with a high near 56. Breezy.
Sunday Night
A chance of rain and snow. Mostly cloudy, with a low around 19. Blustery.
Monday
Partly sunny, with a high near 32.
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Forecast Area
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ABOUT THIS FORECAST

 
Point Forecast:
Harristown IL
 39.85°N 89.08°W (Elev. 653 ft)
Last Update:
4:36 am CDT Mar 10, 2026
Forecast Valid:
5am CDT Mar 10, 2026-6pm CDT Mar 16, 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