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

78°F

26°C

Humidity 74%
Wind Speed Calm
Barometer 29.98 in (1014.7 mb)
Dewpoint 69°F (21°C)
Visibility 10.00 mi
Heat Index80°F (27°C)
Last update 12 Jul 8:54 pm CDT
Extended Forecast for

3 Miles SW Harristown IL

  • Tonight

    Tonight: Partly cloudy, with a low around 69. West wind around 5 mph becoming calm in the evening.

    Low: 69 °F

    Partly Cloudy

  • Sunday

    Sunday: A 30 percent chance of showers and thunderstorms, mainly between 3pm and 5pm. Partly sunny, with a high near 85. Calm wind becoming south southwest around 5 mph in the afternoon.

    High: 85 °F

    Mostly Sunny
    then Chance
    Showers

  • Sunday Night

    Sunday Night: A 10 percent chance of showers before 7pm. Partly cloudy, with a low around 68. Calm wind.

    Low: 68 °F

    Slight Chance
    Showers then
    Partly Cloudy

  • Monday

    Monday: Mostly sunny, with a high near 88. Calm wind becoming south southeast around 5 mph in the morning.

    High: 88 °F

    Mostly Sunny

  • Monday Night

    Monday Night: Partly cloudy, with a low around 70. Light southeast wind.

    Low: 70 °F

    Partly Cloudy

  • Tuesday

    Tuesday: A 40 percent chance of showers and thunderstorms after 1pm. Mostly sunny, with a high near 87. South wind 5 to 8 mph.

    High: 87 °F

    Mostly Sunny
    then Chance
    T-storms

  • Tuesday Night

    Tuesday Night: A 30 percent chance of showers and thunderstorms. Mostly cloudy, with a low around 72. South wind around 6 mph.

    Low: 72 °F

    Chance
    T-storms

  • Wednesday

    Wednesday: A chance of showers and thunderstorms, then showers likely and possibly a thunderstorm after 1pm. Partly sunny, with a high near 88. Chance of precipitation is 60%.

    High: 88 °F

    Chance
    T-storms then
    Showers
    Likely

  • Wednesday Night

    Wednesday Night: A 40 percent chance of showers and thunderstorms before 1am. Partly cloudy, with a low around 71.

    Low: 71 °F

    Chance
    T-storms

Detailed Forecast

Tonight
Partly cloudy, with a low around 69. West wind around 5 mph becoming calm in the evening.
Sunday
A 30 percent chance of showers and thunderstorms, mainly between 3pm and 5pm. Partly sunny, with a high near 85. Calm wind becoming south southwest around 5 mph in the afternoon.
Sunday Night
A 10 percent chance of showers before 7pm. Partly cloudy, with a low around 68. Calm wind.
Monday
Mostly sunny, with a high near 88. Calm wind becoming south southeast around 5 mph in the morning.
Monday Night
Partly cloudy, with a low around 70. Light southeast wind.
Tuesday
A 40 percent chance of showers and thunderstorms after 1pm. Mostly sunny, with a high near 87. South wind 5 to 8 mph.
Tuesday Night
A 30 percent chance of showers and thunderstorms. Mostly cloudy, with a low around 72. South wind around 6 mph.
Wednesday
A chance of showers and thunderstorms, then showers likely and possibly a thunderstorm after 1pm. Partly sunny, with a high near 88. Chance of precipitation is 60%.
Wednesday Night
A 40 percent chance of showers and thunderstorms before 1am. Partly cloudy, with a low around 71.
Thursday
A 40 percent chance of showers and thunderstorms. Mostly sunny, with a high near 87.
Thursday Night
Mostly cloudy, with a low around 67.
Friday
Partly sunny, with a high near 84.
Friday Night
Partly cloudy, with a low around 67.
Saturday
Mostly sunny, with a high near 86.
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Forecast Area
Tiles ©ESRI

ABOUT THIS FORECAST

 
Point Forecast:
3 Miles SW Harristown IL
 39.8°N 89.12°W (Elev. 594 ft)
Last Update:
5:41 pm CDT Jul 12, 2025
Forecast Valid:
9pm CDT Jul 12, 2025-6pm CDT Jul 19, 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