National Oceanic and Atmospheric Administration National Weather Service United States Department of Commerce

Hazardous Weather Conditions

Current conditions at

Decatur Airport (KDEC)

Lat: 39.83°NLon: 88.87°WElev: 670ft.

Fair

71°F

22°C

Humidity 94%
Wind Speed S 5 mph
Barometer 30.03 in (1016.1 mb)
Dewpoint 69°F (21°C)
Visibility 10.00 mi
Last update 9 Aug 4:54 am CDT
Extended Forecast for

Decatur IL

  • Today

    Today: A 20 percent chance of showers and thunderstorms after 1pm. Mostly sunny, with a high near 89. South wind 5 to 10 mph increasing to 11 to 16 mph in the afternoon. Winds could gust as high as 24 mph.

    High: 89 °F

    Mostly Sunny
    then Slight
    Chance
    T-storms

  • Tonight

    Tonight: A 30 percent chance of showers, mainly between 11pm and 5am. Partly cloudy, with a low around 74. South wind 11 to 15 mph, with gusts as high as 24 mph.

    Low: 74 °F

    Chance
    Showers

  • Monday

    Monday: A slight chance of showers before 7am, then a slight chance of showers and thunderstorms after 5pm. Mostly sunny, with a high near 91. Heat index values as high as 102. South southwest wind around 11 mph, with gusts as high as 21 mph. Chance of precipitation is 10%.

    High: 91 °F

    Slight Chance
    Showers then
    Slight Chance
    T-storms

  • Monday Night

    Monday Night: A 30 percent chance of showers after 1am. Partly cloudy, with a low around 75. South southwest wind 7 to 10 mph, with gusts as high as 16 mph.

    Low: 75 °F

    Partly Cloudy
    then Chance
    Showers

  • Tuesday

    Tuesday: Mostly sunny, with a high near 91. Southwest wind around 10 mph, with gusts as high as 16 mph.

    High: 91 °F

    Mostly Sunny

  • Tuesday Night

    Tuesday Night: Showers likely and possibly a thunderstorm after 1am. Partly cloudy, with a low around 73. South southwest wind 5 to 7 mph. Chance of precipitation is 60%. New rainfall amounts of less than a tenth of an inch, except higher amounts possible in thunderstorms.

    Low: 73 °F

    Partly Cloudy
    then Showers
    Likely

  • Wednesday

    Wednesday: Showers likely, with thunderstorms also possible after 1pm. Partly sunny, with a high near 88. West wind around 8 mph. Chance of precipitation is 60%. New rainfall amounts between a quarter and half of an inch possible.

    High: 88 °F

    Showers
    Likely

  • Wednesday Night

    Wednesday Night: Showers likely and possibly a thunderstorm before 1am, then a chance of showers and thunderstorms after 1am. Mostly cloudy, with a low around 69. Chance of precipitation is 60%.

    Low: 69 °F

    Showers
    Likely

  • Thursday

    Thursday: A chance of showers, then showers likely and possibly a thunderstorm after 1pm. Mostly cloudy, with a high near 82. Chance of precipitation is 60%.

    High: 82 °F

    Showers
    Likely

Detailed Forecast

Today
A 20 percent chance of showers and thunderstorms after 1pm. Mostly sunny, with a high near 89. South wind 5 to 10 mph increasing to 11 to 16 mph in the afternoon. Winds could gust as high as 24 mph.
Tonight
A 30 percent chance of showers, mainly between 11pm and 5am. Partly cloudy, with a low around 74. South wind 11 to 15 mph, with gusts as high as 24 mph.
Monday
A slight chance of showers before 7am, then a slight chance of showers and thunderstorms after 5pm. Mostly sunny, with a high near 91. Heat index values as high as 102. South southwest wind around 11 mph, with gusts as high as 21 mph. Chance of precipitation is 10%.
Monday Night
A 30 percent chance of showers after 1am. Partly cloudy, with a low around 75. South southwest wind 7 to 10 mph, with gusts as high as 16 mph.
Tuesday
Mostly sunny, with a high near 91. Southwest wind around 10 mph, with gusts as high as 16 mph.
Tuesday Night
Showers likely and possibly a thunderstorm after 1am. Partly cloudy, with a low around 73. South southwest wind 5 to 7 mph. Chance of precipitation is 60%. New rainfall amounts of less than a tenth of an inch, except higher amounts possible in thunderstorms.
Wednesday
Showers likely, with thunderstorms also possible after 1pm. Partly sunny, with a high near 88. West wind around 8 mph. Chance of precipitation is 60%. New rainfall amounts between a quarter and half of an inch possible.
Wednesday Night
Showers likely and possibly a thunderstorm before 1am, then a chance of showers and thunderstorms after 1am. Mostly cloudy, with a low around 69. Chance of precipitation is 60%.
Thursday
A chance of showers, then showers likely and possibly a thunderstorm after 1pm. Mostly cloudy, with a high near 82. Chance of precipitation is 60%.
Thursday Night
Showers likely and possibly a thunderstorm. Mostly cloudy, with a low around 65. Chance of precipitation is 60%.
Friday
A chance of showers. Mostly cloudy, with a high near 79.
Friday Night
A chance of showers. Mostly cloudy, with a low around 65.
Saturday
A chance of showers. Partly sunny, with a high near 81.
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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:
4:15 am CDT Aug 9, 2026
Forecast Valid:
5am CDT Aug 9, 2026-6pm CDT Aug 15, 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