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.

A Few Clouds

80°F

27°C

Humidity 51%
Wind Speed N 9 mph
Barometer 30.05 in (1017.0 mb)
Dewpoint 60°F (16°C)
Visibility 10.00 mi
Heat Index81°F (27°C)
Last update 17 Aug 3:54 pm CDT
Extended Forecast for

Decatur IL

  • Tonight

    Tonight: Partly cloudy, with a low around 61. North northwest wind 5 to 8 mph becoming calm in the evening.

    Low: 61 °F

    Partly Cloudy

  • Tuesday

    Tuesday: Mostly sunny, with a high near 82. Calm wind becoming west southwest around 6 mph in the morning.

    High: 82 °F

    Mostly Sunny

  • Tuesday Night

    Tuesday Night: A 50 percent chance of showers and thunderstorms after 1am. Mostly cloudy, with a low around 67. South southwest wind 3 to 5 mph.

    Low: 67 °F

    Mostly Cloudy
    then Chance
    T-storms

  • Wednesday

    Wednesday: A chance of showers, with thunderstorms also possible after 1pm. Mostly cloudy, with a high near 81. Calm wind becoming east northeast around 5 mph in the afternoon. Chance of precipitation is 50%.

    High: 81 °F

    Chance
    Showers then
    Chance
    T-storms

  • Wednesday Night

    Wednesday Night: Mostly cloudy, with a low around 63. Northeast wind 3 to 6 mph.

    Low: 63 °F

    Mostly Cloudy

  • Thursday

    Thursday: Mostly sunny, with a high near 81. Northeast wind around 6 mph.

    High: 81 °F

    Mostly Sunny

  • Thursday Night

    Thursday Night: Mostly clear, with a low around 61. Northeast wind around 5 mph becoming calm in the evening.

    Low: 61 °F

    Mostly Clear

  • Friday

    Friday: Sunny, with a high near 82.

    High: 82 °F

    Sunny

  • Friday Night

    Friday Night: Mostly clear, with a low around 63.

    Low: 63 °F

    Mostly Clear

Detailed Forecast

Tonight
Partly cloudy, with a low around 61. North northwest wind 5 to 8 mph becoming calm in the evening.
Tuesday
Mostly sunny, with a high near 82. Calm wind becoming west southwest around 6 mph in the morning.
Tuesday Night
A 50 percent chance of showers and thunderstorms after 1am. Mostly cloudy, with a low around 67. South southwest wind 3 to 5 mph.
Wednesday
A chance of showers, with thunderstorms also possible after 1pm. Mostly cloudy, with a high near 81. Calm wind becoming east northeast around 5 mph in the afternoon. Chance of precipitation is 50%.
Wednesday Night
Mostly cloudy, with a low around 63. Northeast wind 3 to 6 mph.
Thursday
Mostly sunny, with a high near 81. Northeast wind around 6 mph.
Thursday Night
Mostly clear, with a low around 61. Northeast wind around 5 mph becoming calm in the evening.
Friday
Sunny, with a high near 82.
Friday Night
Mostly clear, with a low around 63.
Saturday
Mostly sunny, with a high near 81.
Saturday Night
Mostly clear, with a low around 61.
Sunday
Mostly sunny, with a high near 78.
Sunday Night
Partly cloudy, with a low around 59.
Monday
Partly sunny, with a high near 79.
Basemap Options
Click map to change the forecast location
Loading map...
Forecast Area
Tiles ©ESRI

ABOUT THIS FORECAST

 
Point Forecast:
Decatur IL
 39.84°N 88.94°W (Elev. 692 ft)
Last Update:
3:36 pm CDT Aug 17, 2026
Forecast Valid:
4pm CDT Aug 17, 2026-6pm CDT Aug 24, 2026
 
Forecast Discussion
 
Get as KML Get as XML

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