What is today's weather forecast for Dekalb, IL?

Today's forecast for Dekalb shows a high of 25 degrees and a low of 3 degrees Fahrenheit. Patchy fog before 8am.

What is the 7-day weather forecast for Dekalb, IL?

The 7-day forecast for Dekalb shows highs from 6 to 42 degrees and lows from -7 to 32 degrees Fahrenheit. Expect precipitation on 3 days with chances of 20% or higher.

Will it rain in Dekalb, IL this week?

Yes, rain is possible in Dekalb this week. Precipitation chances: Saturday (60% chance), Wednesday (50% chance), Thursday (50% chance).

How accurate is the Dekalb weather forecast?

WeatherForYou provides highly accurate Dekalb forecasts using National Weather Service data and current conditions from the nearest available weather stations, often miles closer than regional airports, for the most precise local forecasts.

Dekalb, IL Weather Forecast and Current Conditions

Current Conditions From Nearby Local Station

Switch to Metric Units

15°F
Feels Like 15°F

Humidity 93% Dew Point 13°F Wind Calm Barometer 30.07 in.

Visibility 10 mi.

Report from a NOAA weather station 2.6 mi. E of central Dekalb
at 5:35 AM Fri, Dec 12, 2025

Point Forecast at a Glance

FriDec 12

SatDec 13

60%

-7

SunDec 14

-4

MonDec 15

TueDec 16

WedDec 17

ThuDec 18

50%

Jump to detailed forecast ↓

7-Day Temperature Trend

Week Ahead Summary

High temperatures dip from 25°F to a low of 6°F mid-week, then warm to 42°F. Some precipitation possible, including both rain and snow.

Climate Context

This week's forecast shows temperatures running 10°F below the historical average for December. Normal highs for this period are around 35°F with lows around 20°F.

This Date in Weather History

1967 - From December 12th through the 20th a series of snowstorms buries Flagstaff, AZ with nearly 85 inches of snow.

Dekalb, IL 7 Day Weather Forecast Details

Friday Dec 12

Day: Patchy fog before 8am. Otherwise, increasing clouds, with a high near 25. North northeast wind 5 to 10 mph becoming west southwest in the morning. Winds could gust as high as 15 mph.

Night: Mostly cloudy, with a low around 3. Wind chill values as low as -11. Northwest wind 10 to 15 mph, with gusts as high as 25 mph.

Saturday Dec 13

Day: Snow likely, mainly after 9am. Cloudy and cold, with a high near 8. Wind chill values as low as -11. Northwest wind around 10 mph, with gusts as high as 20 mph. Chance of precipitation is 60%. New snow accumulation of less than one inch possible.

Night: Mostly clear, with a low around -7. Wind chill values as low as -26. Northwest wind 10 to 15 mph, with gusts as high as 20 mph.

Sunday Dec 14

Day: Sunny and cold, with a high near 6. Northwest wind 5 to 15 mph, with gusts as high as 20 mph.

Night: Partly cloudy, with a low around -4.

Monday Dec 15

Day: Partly sunny, with a high near 20.

Night: Partly cloudy, with a low around 11.

Tuesday Dec 16

Day: Partly sunny, with a high near 35.

Night: Mostly cloudy, with a low around 29.

Wednesday Dec 17

Day: Mostly cloudy, with a high near 42.

Night: A chance of rain. Mostly cloudy, with a low around 32.

Thursday Dec 18

Day: A chance of rain. Partly sunny, with a high near 42.

How We Provide Better Local Weather

Current conditions: We use the nearest available station to your location - including professional MESONET/MADIS and local weather stations - often miles closer than regional airports.

Forecasts: National Weather Service point forecasts predict for your specific area, not broad regional zones, making them far more relevant to your location.

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