NWS Forecast for De Kalb IL

National Weather Service Forecast for: De Kalb IL
Issued by: National Weather Service Chicago, IL

Updated: 4:06 am CST Dec 5, 2025

Today Partly Sunny	Tonight Patchy Wintry Mix	Saturday Partly Sunny	Saturday Night Chance Snow then Snow	Sunday Chance Snow then Mostly Sunny	Sunday Night Mostly Cloudy	Monday Partly Sunny	Monday Night Chance Snow	Tuesday Mostly Cloudy
Hi 25 °F	Lo 21 °F	Hi 23 °F⇓	Lo 14 °F	Hi 22 °F	Lo 1 °F	Hi 19 °F	Lo 12 °F	Hi 34 °F

Hazardous Weather Outlook
Hydrologic Outlook

Today	Partly sunny, with a high near 25. Wind chill values as low as -9. South southwest wind 10 to 15 mph, with gusts as high as 20 mph.
Tonight	Patchy snow and freezing rain before 3am. Mostly cloudy, with a low around 21. South southwest wind 10 to 15 mph becoming west northwest after midnight. Winds could gust as high as 20 mph. Chance of precipitation is 30%.
Saturday	Partly sunny, with a temperature falling to around 19 by 5pm. Northwest wind 5 to 10 mph becoming light and variable in the afternoon.
Saturday Night	Snow, mainly after midnight. Low around 14. Calm wind becoming northeast around 5 mph after midnight. Winds could gust as high as 10 mph. Chance of precipitation is 80%. New snow accumulation of 1 to 3 inches possible.
Sunday	A 50 percent chance of snow before noon. Partly sunny, with a high near 22. North wind 5 to 10 mph, with gusts as high as 20 mph.
Sunday Night	Mostly cloudy, with a low around 1.
Monday	Partly sunny, with a high near 19.
Monday Night	A chance of snow. Mostly cloudy, with a low around 12.
Tuesday	Mostly cloudy, with a high near 34.
Tuesday Night	Snow likely. Cloudy, with a low around 27.
Wednesday	A chance of rain and snow. Mostly cloudy, with a high near 34.
Wednesday Night	A chance of snow. Mostly cloudy, with a low around 10.
Thursday	Partly sunny, with a high near 20.

Forecast from NOAA-NWS for De Kalb IL.