DeKalb County, IL Weather Forecast
County weather hub
Sunny
Compare major city weather across DeKalb County, scan the latest forecast snapshots, and jump into local 7-day outlook pages from one hub.
Sunny. High near 77, with temperatures falling to around 75 in the afternoon. West wind 5 to 10 mph.
County Weather Overview
This county weather page brings together forecast coverage for DeKalb County so visitors can compare temperatures, wind, and conditions across the region without hopping between unrelated pages.
Current forecast coverage spans 6 of 6 mapped cities in DeKalb County.
Page Snapshot
- Page focus
- county weather
- Forecast window
- Oct 13 to Oct 19, 2026
- Latest sync
- Oct 13, 2026 4:40 PM CDT
- Forecast office
- LOT
- Source
- NOAA / NWS
Daily Outlook
This Week in DeKalb County
This Afternoon looks like the warmest upcoming period in DeKalb County at 77 degrees F.
Friday Night is the coolest period ahead with temperatures near 33 degrees F.
The strongest winds are forecast for Friday at about 20 to 25 mph NW.
Precipitation is mentioned in 6 upcoming forecast periods.
Forecast Details
- Last updated
- Oct 13, 2026 4:40 PM CDT
- Coverage
- 7 days
- Time zone
- America/Chicago
- Forecast office
- LOT
- Radar station
- KLOT
Weather data is provided by the National Weather Service and refreshed automatically for U.S. locations.
Open NOAA sourceExtended Forecast
A slight chance of showers and thunderstorms between 8pm and 9pm, then showers and thunderstorms likely. Mostly cloudy, with a low around 59. North northwest wind 0 to 10 mph. Chance of precipitation is 70%. New rainfall amounts between a quarter and half of an inch possible.
A slight chance of showers and thunderstorms before 2pm. Mostly cloudy. High near 66, with temperatures falling to around 64 in the afternoon. Northeast wind 5 to 10 mph, with gusts as high as 20 mph. Chance of precipitation is 20%. New rainfall amounts between a tenth and quarter of an inch possible.
A slight chance of rain showers after 5am. Mostly cloudy, with a low around 54. East northeast wind around 10 mph, with gusts as high as 20 mph. Chance of precipitation is 20%.
A chance of rain showers before 7am, then showers and thunderstorms. Cloudy, with a high near 62. East wind 5 to 10 mph. Chance of precipitation is 100%.
Rain showers before 1am. Mostly cloudy, with a low around 45. Chance of precipitation is 100%.
Mostly sunny, with a high near 56.
Areas of frost after 3am. Mostly clear, with a low around 33.
Areas of frost before 8am. Sunny, with a high near 59.
Clear, with a low around 40.
Sunny, with a high near 66.
Partly cloudy, with a low around 46.
A slight chance of rain showers between 7am and 1pm. Partly sunny, with a high near 68.
Mostly cloudy, with a low around 47.
Detailed Forecast
| Period | Conditions | Temp | Wind |
|---|---|---|---|
|
This Afternoon
Oct 13
|
Sunny
|
77°F |
5 to 10 mph
W
|
|
Tonight
Oct 13
|
Slight Chance Showers And Thunderstorms then Showers And Thunderstorms Likely
|
59°F |
0 to 10 mph
NNW
|
|
Wednesday
Oct 14
|
Slight Chance Showers And Thunderstorms
|
66°F |
5 to 10 mph
NE
|
|
Wednesday Night
Oct 14
|
Mostly Cloudy then Slight Chance Rain Showers
|
54°F |
10 mph
ENE
|
|
Thursday
Oct 15
|
Showers And Thunderstorms
|
62°F |
5 to 10 mph
E
|
|
Thursday Night
Oct 15
|
Rain Showers
|
45°F |
5 to 20 mph
N
|
|
Friday
Oct 16
|
Mostly Sunny
|
56°F |
20 to 25 mph
NW
|
|
Friday Night
Oct 16
|
Mostly Clear then Areas Of Frost
|
33°F |
0 to 15 mph
NNW
|
|
Saturday
Oct 17
|
Areas Of Frost then Sunny
|
59°F |
0 to 10 mph
W
|
|
Saturday Night
Oct 17
|
Clear
|
40°F |
5 to 10 mph
SSW
|
|
Sunday
Oct 18
|
Sunny
|
66°F |
10 to 15 mph
SSW
|
|
Sunday Night
Oct 18
|
Partly Cloudy
|
46°F |
5 to 15 mph
SSW
|
|
Monday
Oct 19
|
Slight Chance Rain Showers
|
68°F |
5 to 10 mph
SW
|
|
Monday Night
Oct 19
|
Mostly Cloudy
|
47°F |
0 to 5 mph
S
|
Major City Forecasts
Live forecast snapshots for major cities across DeKalb County.
Coverage
Forecast coverage currently spans 6 of 6 mapped cities in DeKalb County.
Largest mapped city population in this region: 42,621.
