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

79°F

26°C

Humidity 74%
Wind Speed NE 9 mph
Barometer 29.85 in (1010.2 mb)
Dewpoint 70°F (21°C)
Visibility 10.00 mi
Heat Index82°F (28°C)
Last update 28 Jul 5:54 pm CDT
Extended Forecast for

Decatur IL

  • Tonight

    Tonight: Mostly clear, with a low around 62. Northeast wind 3 to 7 mph.

    Low: 62 °F

    Mostly Clear

  • Wednesday

    Wednesday: Sunny, with a high near 84. Light north northeast wind increasing to 5 to 9 mph in the morning.

    High: 84 °F

    Sunny

  • Wednesday Night

    Wednesday Night: Clear, with a low around 62. North northeast wind 5 to 7 mph becoming calm in the evening.

    Low: 62 °F

    Clear

  • Thursday

    Thursday: Sunny, with a high near 86. Light and variable wind.

    High: 86 °F

    Sunny

  • Thursday Night

    Thursday Night: Partly cloudy, with a low around 65. Calm wind becoming south southeast around 5 mph after midnight.

    Low: 65 °F

    Partly Cloudy

  • Friday

    Friday: A 50 percent chance of showers after 1pm. Mostly cloudy, with a high near 82. South southeast wind 5 to 10 mph, with gusts as high as 16 mph.

    High: 82 °F

    Partly Sunny
    then Chance
    Showers

  • Friday Night

    Friday Night: Showers likely and possibly a thunderstorm. Mostly cloudy, with a low around 67. Southeast wind 10 to 13 mph, with gusts as high as 17 mph. Chance of precipitation is 70%. New rainfall amounts between a quarter and half of an inch possible.

    Low: 67 °F

    Showers
    Likely

  • Saturday

    Saturday: Showers likely, with thunderstorms also possible after 1pm. Mostly cloudy, with a high near 77. Chance of precipitation is 60%.

    High: 77 °F

    Showers
    Likely

  • Saturday Night

    Saturday Night: A 30 percent chance of showers before 1am. Partly cloudy, with a low around 65.

    Low: 65 °F

    Chance
    Showers

Detailed Forecast

Tonight
Mostly clear, with a low around 62. Northeast wind 3 to 7 mph.
Wednesday
Sunny, with a high near 84. Light north northeast wind increasing to 5 to 9 mph in the morning.
Wednesday Night
Clear, with a low around 62. North northeast wind 5 to 7 mph becoming calm in the evening.
Thursday
Sunny, with a high near 86. Light and variable wind.
Thursday Night
Partly cloudy, with a low around 65. Calm wind becoming south southeast around 5 mph after midnight.
Friday
A 50 percent chance of showers after 1pm. Mostly cloudy, with a high near 82. South southeast wind 5 to 10 mph, with gusts as high as 16 mph.
Friday Night
Showers likely and possibly a thunderstorm. Mostly cloudy, with a low around 67. Southeast wind 10 to 13 mph, with gusts as high as 17 mph. Chance of precipitation is 70%. New rainfall amounts between a quarter and half of an inch possible.
Saturday
Showers likely, with thunderstorms also possible after 1pm. Mostly cloudy, with a high near 77. Chance of precipitation is 60%.
Saturday Night
A 30 percent chance of showers before 1am. Partly cloudy, with a low around 65.
Sunday
A 30 percent chance of showers after 1pm. Mostly sunny, with a high near 82.
Sunday Night
Partly cloudy, with a low around 64.
Monday
Sunny, with a high near 84.
Monday Night
Mostly clear, with a low around 67.
Tuesday
A chance of showers. Mostly sunny, with a high near 87.
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:
5:22 pm CDT Jul 28, 2026
Forecast Valid:
5pm CDT Jul 28, 2026-6pm CDT Aug 4, 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