January weather forecast
DeKalb, IL

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Weather in January

January weather in DeKalb, Illinois, is characterized by the chilling cold, with snowfall reaching a significant 5.55" (141mm). Typically, the town experiences its seasonal winter, inducing substantial cloud coverage. The short daylight hours compound the prevailing frostiness; people can sense nature's winter hibernation, the decreased daylight hours lending an icy white color palette to the landscape. Higher wind speeds are noted, with gusts brushing against snow-laden trees. The chilly January weather is best spent indoors with a good heater, keeping the cold at bay.

Temperature

January stands out as DeKalb's coldest month, with temperatures ranging between an average high of 27°F (-2.8°C) and a low of 15.1°F (-9.4°C).

Humidity

The months with the highest humidity are January and July, with an average relative humidity of 85%.

Rainfall

In DeKalb, in January, during 5.7 rainfall days, 1.81" (46mm) of precipitation is typically accumulated. Throughout the year, there are 152.6 rainfall days, and 32.09" (815mm) of precipitation is accumulated.

Snowfall

Months with snowfall in DeKalb are January through May, October through December. The month with the most snowfall is January, when snow falls for 11.8 days and typically aggregates up to 5.55" (141mm) of snow.

Daylight

In DeKalb, Illinois, the average length of the day in January is 9h and 32min.
On the first day of January, sunrise is at 7:22 am and sunset at 4:34 pm. On the last day of the month, sunrise is at 7:08 am and sunset at 5:08 pm CST.

Sunshine

The month with the least sunshine is January, with an average of 3.6h of sunshine.

UV index

January and December, with an average maximum UV index of 1, are months with the lowest UV index. A UV Index estimate of 2, and below, represents a minimal health hazard from exposure to the Sun's UV rays for the ordinary person.
Note: In January, the maximum UV index of 1 translates into these guidelines:
Most individuals face no major issues with lengthy exposure to the sun, but children, infants, and individuals with fair skin always require protection. The solar radiation around mid-day is intense; avoid the Sun and stay safe. A hat with a generous brim can prevent nearly 50% of UV rays from reaching your eyes. Be aware! The intensity of the Sun's UV radiation can be amplified nearly twice due to snow reflection.
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Frequently asked questions

What part of the year is the coldest in DeKalb?

With average high and low temperatures of 27°F (-2.8°C) and 15.1°F (-9.4°C) respectively, January is DeKalb's coldest month.

How cold is January in DeKalb?

During January, DeKalb experiences an average high-temperature of 27°F (-2.8°C) and a low-temperature of 15.1°F (-9.4°C).

What are the most humid months in DeKalb?

January and July, with an average relative humidity of 85%, are most humid months in DeKalb.

What is the average humidity in January in DeKalb?

The average relative humidity in January in DeKalb, Illinois, is 85%.

How many days does it rain in January in DeKalb?

In DeKalb, during January, the rain falls for 5.7 days and regularly aggregates up to 1.81" (46mm) of precipitation.

What is the snowiest month in DeKalb?

January is the month with the most snowfall in DeKalb, Illinois. Snow falls for 11.8 days and accumulates 5.55" (141mm) of snow.

How many days does it snow in January in DeKalb?

In DeKalb, Illinois, in January, during 11.8 snowfall days, 5.55" (141mm) of snow is typically accumulated.

What is the average length of the day in January in DeKalb?

The average day length in January in DeKalb is 9h and 32min.

When are sunrise and sunset in January in DeKalb?

On the first day of January in DeKalb, Illinois, sunrise is at 7:22 am and sunset at 4:34 pm. On the last day of the month, sunrise is at 7:08 am and sunset at 5:08 pm CST.

What is the month with the least sunshine in DeKalb?

With an average of 3.6h of sunshine, January has the least sunshine of the year.

How many hours of sunshine does DeKalb have in January?

In DeKalb, Illinois, the average sunshine duration in January is 3.6h.

What is the month with the lowest UV index in DeKalb?

January and December, with an average maximum UV index of 1, are months with the lowest UV index in DeKalb.

What is the UV index intensity in January in DeKalb?

In January, the average daily maximum UV index is 1. A UV Index of 2, and less, symbolizes a low health risk from exposure to Sun's UV rays.
Today
Tomorrow
Long-term
YearJanuaryFMAMJJASOND
Dec
January
Feb
Average high temperature
33.1°F 0.6°C
27°F -2.8°C
31.1°F -0.5°C
Average low temperature
23°F -5°C
15.1°F -9.4°C
18.1°F -7.7°C
Average pressure
30.1" 765mmHg
30.11" 765mmHg
30.1" 765mmHg
Average wind speed
9.3mph 15km/h
9.9mph 15.9km/h
9.9mph 15.9km/h
Average max. wind speed
10mph 16.1km/h
10.6mph 17.1km/h
10.6mph 17.1km/h
Average wind speed gusts
14.7mph 23.7km/h
15.6mph 25.1km/h
15.6mph 25.1km/h
Average humidity
83%
85%
84%
Average rainfall
1.69" 43mm
1.81" 46mm
1.65" 42mm
Average rainfall days
8.5
5.7
4.7
Average snowfall
2.91" 74mm
5.55" 141mm
3.86" 98mm
Average snowfall days
10
11.8
10.6
Average daylight
9h 1min
9h 3min
10h 4min
Average sunshine
3h 5min
3h 4min
3h 5min
Average sunshine days
15.5
14.6
13.4
Average UV index
1
1
2
Average cloud cover
59%
63%
59%
Average visibility
6mi 9.7km
5mi 8km
5mi 8km

Average temperature in January
DeKalb, IL

Average temperature in January - DeKalb, IL
  • Average high temperature in January: 27°F

The warmest month (with the highest average high temperature) is July (80.2°F).
The month with the lowest average high temperature is January (27°F).

  • Average low temperature in January: 15.1°F

The month with the highest average low temperature is July (63.1°F).
The coldest month (with the lowest average low temperature) is January (15.1°F).

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Average pressure in January
DeKalb, IL

Average pressure in January - DeKalb, IL
  • Average pressure in January: 30.11"Hg

The month with the highest atmospheric pressure is January (30.11"Hg).
The month with the lowest atmospheric pressure is June (29.92"Hg).

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Average wind speed in January
DeKalb, IL

Average wind speed in January - DeKalb, IL
  • Average wind speed in January: 9.9mph

The windiest month (with the highest average wind speed) is April (10mph).
The calmest month (with the lowest average wind speed) is August (6.2mph).

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Average humidity in January
DeKalb, IL

Average humidity in January - DeKalb, IL
  • Average humidity in January: 85%

The months with the highest relative humidity are January and July (85%).
The months with the lowest relative humidity are April and October (75%).

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Average rainfall in January
DeKalb, IL

Average rainfall in January - DeKalb, IL
  • Average rainfall in January: 1.81"

The wettest month (with the highest rainfall) is May (4.37").
The driest month (with the least rainfall) is February (1.65").

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Average rainfall days in January
DeKalb, IL

Average rainfall days in January - DeKalb, IL
  • Average rainfall days in January: 5.7 days

The month with the highest number of rainy days is May (18.3 days).
The month with the least rainy days is February (4.7 days).

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Average snowfall in January
DeKalb, IL

Average snowfall in January - DeKalb, IL
  • Average snowfall in January: 5.55"

The month with the highest snowfall is January (5.55").
The months with the least snowfall are June, July, August and September (0").

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Average snowfall days in January
DeKalb, IL

Average snowfall days in January - DeKalb, IL
  • Average snowfall days in January: 11.8 days

The month with the highest number of snowfall days is January (11.8 days).
The months with the least snowfall days are June, July, August and September (0 days).

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Average daylight in January /
Average sunshine in January
DeKalb, IL

Average daylight in January / Average sunshine in January - DeKalb, IL
  • Average daylight in January: 9h and 3min

The month with the longest days is June (Average daylight: 15h and 12min).
The month with the shortest days is December (Average daylight: 9h and 12min).

  • Average sunshine in January: 3h and 4min

The month with the most sunshine is July (Average sunshine: 9h and 36min).
The month with the least sunshine is January (Average sunshine: 3h and 36min).

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Average sunshine days in January
DeKalb, IL

Average sunshine days in January - DeKalb, IL
  • Average sunshine days in January: 14.6 days

The month with the most sunshine days is November (17.2 days).
The months with the least sunshine days are June and July (10.3 days).

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Average UV index in January
DeKalb, IL

Average UV index in January - DeKalb, IL
  • Average UV index in January: 1

The months with the highest UV index are June and August (UV index 6).
The months with the lowest UV index are January and December (UV index 1).

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Average cloud cover in January
DeKalb, IL

Average cloud cover in January - DeKalb, IL
  • Average cloud cover in January: 63

The month with the most cloud cover is January (Cloud cover 63).
The months with the least cloud cover are August and September (Cloud cover 35).

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Average visibility in January
DeKalb, IL

Average visibility in January - DeKalb, IL
  • Average visibility in January: 5mi

The months with the highest visibility are March, April, May, June, October, November and December (6mi).
The months with the lowest visibility are January, February, July, August and September (5mi).

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DeKalb, Illinois, USA

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