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

77°F

25°C

Humidity 40%
Wind Speed E 14 G 24 mph
Barometer 29.90 in (1012.2 mb)
Dewpoint 51°F (11°C)
Visibility 10.00 mi
Heat Index78°F (26°C)
Last update 26 Apr 3:54 pm CDT
Extended Forecast for

Decatur IL

  • Tonight

    Tonight: A 20 percent chance of showers and thunderstorms after 4am. Mostly cloudy, with a low around 59. East southeast wind 10 to 14 mph, with gusts as high as 23 mph.

    Low: 59 °F

    Partly Cloudy
    then Slight
    Chance
    T-storms

  • Monday

    Monday: Showers and thunderstorms, mainly after 10am. Some of the storms could be severe. High near 75. Breezy, with a south southeast wind 15 to 24 mph, with gusts as high as 40 mph. Chance of precipitation is 80%. New rainfall amounts between a half and three quarters of an inch possible.

    High: 75 °F

    Severe
    Thunderstorms
    and Breezy

  • Monday Night

    Monday Night: Showers and thunderstorms before 10pm, then showers between 10pm and 1am. Some of the storms could be severe. Low around 52. Breezy, with a south wind 14 to 23 mph becoming west after midnight. Winds could gust as high as 37 mph. Chance of precipitation is 80%. New precipitation amounts between a half and three quarters of an inch possible.

    Low: 52 °F

    Severe
    Thunderstorms
    and Breezy
    then Showers

  • Tuesday

    Tuesday: Mostly sunny, with a high near 66. West wind 8 to 11 mph, with gusts as high as 20 mph.

    High: 66 °F

    Mostly Sunny

  • Tuesday Night

    Tuesday Night: A 50 percent chance of showers. Mostly cloudy, with a low around 49. North wind 6 to 9 mph, with gusts as high as 15 mph.

    Low: 49 °F

    Chance
    Showers

  • Wednesday

    Wednesday: Mostly sunny, with a high near 63. North wind 10 to 14 mph, with gusts as high as 22 mph.

    High: 63 °F

    Mostly Sunny

  • Wednesday Night

    Wednesday Night: Mostly clear, with a low around 42. North northwest wind 5 to 10 mph becoming light north after midnight. Winds could gust as high as 15 mph.

    Low: 42 °F

    Mostly Clear

  • Thursday

    Thursday: Mostly sunny, with a high near 64.

    High: 64 °F

    Mostly Sunny

  • Thursday Night

    Thursday Night: Partly cloudy, with a low around 43.

    Low: 43 °F

    Partly Cloudy

Detailed Forecast

Tonight
A 20 percent chance of showers and thunderstorms after 4am. Mostly cloudy, with a low around 59. East southeast wind 10 to 14 mph, with gusts as high as 23 mph.
Monday
Showers and thunderstorms, mainly after 10am. Some of the storms could be severe. High near 75. Breezy, with a south southeast wind 15 to 24 mph, with gusts as high as 40 mph. Chance of precipitation is 80%. New rainfall amounts between a half and three quarters of an inch possible.
Monday Night
Showers and thunderstorms before 10pm, then showers between 10pm and 1am. Some of the storms could be severe. Low around 52. Breezy, with a south wind 14 to 23 mph becoming west after midnight. Winds could gust as high as 37 mph. Chance of precipitation is 80%. New precipitation amounts between a half and three quarters of an inch possible.
Tuesday
Mostly sunny, with a high near 66. West wind 8 to 11 mph, with gusts as high as 20 mph.
Tuesday Night
A 50 percent chance of showers. Mostly cloudy, with a low around 49. North wind 6 to 9 mph, with gusts as high as 15 mph.
Wednesday
Mostly sunny, with a high near 63. North wind 10 to 14 mph, with gusts as high as 22 mph.
Wednesday Night
Mostly clear, with a low around 42. North northwest wind 5 to 10 mph becoming light north after midnight. Winds could gust as high as 15 mph.
Thursday
Mostly sunny, with a high near 64.
Thursday Night
Partly cloudy, with a low around 43.
Friday
Mostly sunny, with a high near 63.
Friday Night
Partly cloudy, with a low around 40.
Saturday
Sunny, with a high near 64.
Saturday Night
Mostly clear, with a low around 45.
Sunday
Mostly sunny, with a high near 71.
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Forecast Area
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ABOUT THIS FORECAST

 
Point Forecast:
Decatur IL
 39.86°N 88.94°W (Elev. 682 ft)
Last Update:
3:36 pm CDT Apr 26, 2026
Forecast Valid:
4pm CDT Apr 26, 2026-6pm CDT May 3, 2026
 
Forecast Discussion
 
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Additional Resources

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Hourly Weather Forecast

National Digital Forecast Database

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High Temperature

National Digital Forecast Database Weather Element Forecast

Chance of Precipitation