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.

Overcast

64°F

18°C

Humidity 50%
Wind Speed E 18 mph
Barometer 30.13 in (1020.3 mb)
Dewpoint 45°F (7°C)
Visibility 10.00 mi
Last update 21 May 4:54 pm CDT
Extended Forecast for

Decatur IL

  • Tonight

    Tonight: Mostly cloudy, with a low around 53. East wind 9 to 13 mph, with gusts as high as 21 mph.

    Low: 53 °F

    Mostly Cloudy

  • Friday

    Friday: A 40 percent chance of showers, mainly after 2pm. Cloudy, with a high near 70. East northeast wind 10 to 13 mph, with gusts as high as 20 mph.

    High: 70 °F

    Cloudy then
    Chance
    Showers

  • Friday Night

    Friday Night: A 40 percent chance of showers. Cloudy, with a low around 57. North northeast wind 6 to 10 mph, with gusts as high as 16 mph.

    Low: 57 °F

    Chance
    Showers

  • Saturday

    Saturday: Mostly cloudy, with a high near 76. Northwest wind 5 to 7 mph.

    High: 76 °F

    Mostly Cloudy

  • Saturday Night

    Saturday Night: Mostly cloudy, with a low around 59. Northwest wind around 5 mph becoming calm in the evening.

    Low: 59 °F

    Mostly Cloudy

  • Sunday

    Sunday: A chance of showers, with thunderstorms also possible after 1pm. Mostly cloudy, with a high near 80. Calm wind becoming south around 5 mph in the afternoon. Chance of precipitation is 50%.

    High: 80 °F

    Chance
    Showers then
    Chance
    T-storms

  • Sunday Night

    Sunday Night: Mostly cloudy, with a low around 59. Light east northeast wind.

    Low: 59 °F

    Mostly Cloudy

  • Memorial Day

    Memorial Day: Partly sunny, with a high near 80.

    High: 80 °F

    Partly Sunny

  • Monday Night

    Monday Night: Mostly cloudy, with a low around 62.

    Low: 62 °F

    Mostly Cloudy

Detailed Forecast

Tonight
Mostly cloudy, with a low around 53. East wind 9 to 13 mph, with gusts as high as 21 mph.
Friday
A 40 percent chance of showers, mainly after 2pm. Cloudy, with a high near 70. East northeast wind 10 to 13 mph, with gusts as high as 20 mph.
Friday Night
A 40 percent chance of showers. Cloudy, with a low around 57. North northeast wind 6 to 10 mph, with gusts as high as 16 mph.
Saturday
Mostly cloudy, with a high near 76. Northwest wind 5 to 7 mph.
Saturday Night
Mostly cloudy, with a low around 59. Northwest wind around 5 mph becoming calm in the evening.
Sunday
A chance of showers, with thunderstorms also possible after 1pm. Mostly cloudy, with a high near 80. Calm wind becoming south around 5 mph in the afternoon. Chance of precipitation is 50%.
Sunday Night
Mostly cloudy, with a low around 59. Light east northeast wind.
Memorial Day
Partly sunny, with a high near 80.
Monday Night
Mostly cloudy, with a low around 62.
Tuesday
A chance of showers, with thunderstorms also possible after 1pm. Partly sunny, with a high near 82. Chance of precipitation is 40%.
Tuesday Night
A chance of showers and thunderstorms. Mostly cloudy, with a low around 64.
Wednesday
A chance of showers and thunderstorms. Partly sunny, with a high near 81.
Wednesday Night
A chance of showers and thunderstorms. Partly cloudy, with a low around 65.
Thursday
A chance of showers and thunderstorms. Mostly sunny, with a high near 83.
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Forecast Area
Tiles ©ESRI

ABOUT THIS FORECAST

 
Point Forecast:
Decatur IL
 39.86°N 88.94°W (Elev. 682 ft)
Last Update:
2:21 pm CDT May 21, 2026
Forecast Valid:
5pm CDT May 21, 2026-6pm CDT May 28, 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