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Hazardous Weather Conditions

Current conditions at

Decatur Airport (KDEC)

Lat: 39.83°NLon: 88.87°WElev: 670ft.

A Few Clouds

80°F

27°C

Humidity 74%
Wind Speed S 7 mph
Barometer 29.90 in (1011.8 mb)
Dewpoint 71°F (22°C)
Visibility 10.00 mi
Heat Index83°F (28°C)
Last update 16 Jun 6:54 pm CDT
Extended Forecast for

Harristown IL

  • Tonight

    Tonight: Patchy fog after 1am. Otherwise, mostly cloudy, with a low around 67. South wind 3 to 7 mph.

    Low: 67 °F

    Mostly Cloudy
    then Patchy
    Fog

  • Tuesday

    Tuesday: Areas of fog before 9am. Otherwise, mostly sunny, with a high near 87. Light south southwest wind increasing to 5 to 9 mph in the morning.

    High: 87 °F

    Areas Fog
    then Mostly
    Sunny

  • Tuesday Night

    Tuesday Night: A 30 percent chance of showers and thunderstorms before 1am. Mostly cloudy, with a low around 71. South wind 6 to 9 mph, with gusts as high as 15 mph.

    Low: 71 °F

    Chance
    T-storms

  • Wednesday

    Wednesday: Showers and thunderstorms. High near 83. South southwest wind 10 to 16 mph, with gusts as high as 24 mph. Chance of precipitation is 80%. New rainfall amounts between a quarter and half of an inch possible.

    High: 83 °F

    T-storms

  • Wednesday Night

    Wednesday Night: A 40 percent chance of showers and thunderstorms before 1am. Mostly cloudy, with a low around 66. Southwest wind 9 to 14 mph, with gusts as high as 22 mph.

    Low: 66 °F

    Chance
    T-storms

  • Juneteenth

    Juneteenth: Sunny, with a high near 82. West northwest wind around 8 mph.

    High: 82 °F

    Sunny

  • Thursday Night

    Thursday Night: Mostly clear, with a low around 66. Southwest wind 3 to 6 mph.

    Low: 66 °F

    Mostly Clear

  • Friday

    Friday: Sunny, with a high near 87.

    High: 87 °F

    Sunny

  • Friday Night

    Friday Night: Mostly clear, with a low around 73.

    Low: 73 °F

    Mostly Clear

Detailed Forecast

Tonight
Patchy fog after 1am. Otherwise, mostly cloudy, with a low around 67. South wind 3 to 7 mph.
Tuesday
Areas of fog before 9am. Otherwise, mostly sunny, with a high near 87. Light south southwest wind increasing to 5 to 9 mph in the morning.
Tuesday Night
A 30 percent chance of showers and thunderstorms before 1am. Mostly cloudy, with a low around 71. South wind 6 to 9 mph, with gusts as high as 15 mph.
Wednesday
Showers and thunderstorms. High near 83. South southwest wind 10 to 16 mph, with gusts as high as 24 mph. Chance of precipitation is 80%. New rainfall amounts between a quarter and half of an inch possible.
Wednesday Night
A 40 percent chance of showers and thunderstorms before 1am. Mostly cloudy, with a low around 66. Southwest wind 9 to 14 mph, with gusts as high as 22 mph.
Juneteenth
Sunny, with a high near 82. West northwest wind around 8 mph.
Thursday Night
Mostly clear, with a low around 66. Southwest wind 3 to 6 mph.
Friday
Sunny, with a high near 87.
Friday Night
Mostly clear, with a low around 73.
Saturday
Sunny, with a high near 92.
Saturday Night
Mostly clear, with a low around 75.
Sunday
Sunny, with a high near 92.
Sunday Night
Mostly clear, with a low around 74.
Monday
Sunny, with a high near 92.
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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:
6:41 pm CDT Jun 16, 2025
Forecast Valid:
6pm CDT Jun 16, 2025-6pm CDT Jun 23, 2025
 
Forecast Discussion
 
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Additional Resources

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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