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

24°C

76°F

Humidity 82%
Wind Speed SW 6 km/h
Barometer 1015.5 mb (30.01 in)
Dewpoint 21°C (70°F)
Visibility 16 km
Heat Index25°C (77°F)
Last update 12 Jul 9:54 pm CDT
Extended Forecast for

Decatur IL

  • Tonight

    Tonight: Partly cloudy, with a low around 21. Calm wind.

    Low: 21 °C

    Partly Cloudy

  • Sunday

    Sunday: A 30 percent chance of showers and thunderstorms, mainly between 3pm and 5pm. Increasing clouds, with a high near 30. Calm wind becoming west 5 to 10 km/h in the morning.

    High: 30 °C

    Mostly Sunny
    then Chance
    Showers

  • Sunday Night

    Sunday Night: Partly cloudy, with a low around 21. Calm wind.

    Low: 21 °C

    Partly Cloudy

  • Monday

    Monday: Mostly sunny, with a high near 32. Calm wind becoming south southeast 5 to 8 km/h in the morning.

    High: 32 °C

    Mostly Sunny

  • Monday Night

    Monday Night: Partly cloudy, with a low around 22. Calm wind.

    Low: 22 °C

    Partly Cloudy

  • Tuesday

    Tuesday: A 40 percent chance of showers and thunderstorms after 1pm. Mostly sunny, with a high near 31. South wind 8 to 11 km/h.

    High: 31 °C

    Mostly Sunny
    then Chance
    T-storms

  • Tuesday Night

    Tuesday Night: A 30 percent chance of showers and thunderstorms. Mostly cloudy, with a low around 22. South southwest wind 8 to 10 km/h.

    Low: 22 °C

    Chance
    T-storms

  • Wednesday

    Wednesday: A chance of showers and thunderstorms, then showers likely and possibly a thunderstorm after 1pm. Partly sunny, with a high near 32. Chance of precipitation is 60%.

    High: 32 °C

    Chance
    T-storms then
    Showers
    Likely

  • Wednesday Night

    Wednesday Night: A 40 percent chance of showers and thunderstorms before 1am. Partly cloudy, with a low around 22.

    Low: 22 °C

    Chance
    T-storms

Detailed Forecast

Tonight
Partly cloudy, with a low around 21. Calm wind.
Sunday
A 30 percent chance of showers and thunderstorms, mainly between 3pm and 5pm. Increasing clouds, with a high near 30. Calm wind becoming west 5 to 10 km/h in the morning.
Sunday Night
Partly cloudy, with a low around 21. Calm wind.
Monday
Mostly sunny, with a high near 32. Calm wind becoming south southeast 5 to 8 km/h in the morning.
Monday Night
Partly cloudy, with a low around 22. Calm wind.
Tuesday
A 40 percent chance of showers and thunderstorms after 1pm. Mostly sunny, with a high near 31. South wind 8 to 11 km/h.
Tuesday Night
A 30 percent chance of showers and thunderstorms. Mostly cloudy, with a low around 22. South southwest wind 8 to 10 km/h.
Wednesday
A chance of showers and thunderstorms, then showers likely and possibly a thunderstorm after 1pm. Partly sunny, with a high near 32. Chance of precipitation is 60%.
Wednesday Night
A 40 percent chance of showers and thunderstorms before 1am. Partly cloudy, with a low around 22.
Thursday
A chance of showers, with thunderstorms also possible after 1pm. Partly sunny, with a high near 31. Chance of precipitation is 50%.
Thursday Night
A chance of showers and thunderstorms. Mostly cloudy, with a low around 20.
Friday
Partly sunny, with a high near 29.
Friday Night
Partly cloudy, with a low around 19.
Saturday
Mostly sunny, with a high near 30.
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Forecast Area
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ABOUT THIS FORECAST

 
Point Forecast:
Decatur IL
 39.84°N 88.94°W (Elev. 692 m)
Last Update:
5:41 pm CDT Jul 12, 2025
Forecast Valid:
10pm CDT Jul 12, 2025-6pm CDT Jul 19, 2025
 
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