January weather forecastWinnetka, IL

January

Weather in January

January, like December, is another subzero cold winter month in Winnetka, Illinois, with temperature in the range of an average low of 18.9°F (-7.3°C) and an average high of 28.8°F (-1.8°C).

Temperature

Winnetka reaches its lowest average temperatures in January, measuring 28.8°F (-1.8°C) at the peak and 18.9°F (-7.3°C) at the lowest.

Humidity

The most humid month is January, with an average relative humidity of 82%.

Rainfall

In Winnetka, in January, during 7.3 rainfall days, 1.77" (45mm) of precipitation is typically accumulated. Throughout the year, there are 164.7 rainfall days, and 35.28" (896mm) of precipitation is accumulated.

Snowfall

Months with snowfall are January through May, October through December. The month with the most snowfall is January, when snow falls for 13.1 days and typically aggregates up to 4.84" (123mm) of snow.

Daylight

The average length of the day in January is 9h and 32min.
On the first day of the month, sunrise is at 7:19 am and sunset at 4:29 pm. On the last day of January, sunrise is at 7:05 am and sunset at 5:03 pm CST.

Sunshine

With an average of 3.7h of sunshine, January has the least sunshine of the year.

UV index

In Winnetka, the average daily maximum UV index in January is 2. A UV Index estimate of 2, and below, represents a low threat to health from exposure to the Sun's UV radiation for the average person.
Note: In January, the UV index of 2 transforms into the following advice:
Children, babies, and those with sensitive skin should always be shielded from long periods of sun exposure. The most potent solar radiation is around mid-day, so one should minimize exposure to direct sunlight during this period. Employ a hat with a wide brim for robust protection, cutting UV exposure by half. Foresee this! The reflection from snow can nearly double the intensity of UV radiation from the Sun.
Updated: Jul 14, 2024
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate

Frequently asked questions

January stands out as Winnetka's coldest month, with temperatures ranging between an average high of 28.8°F (-1.8°C) and a low of 18.9°F (-7.3°C).

In Winnetka, 28.8°F (-1.8°C) is the average high-temperature and 18.9°F (-7.3°C) is the average low-temperature during January.

January is the most humid month, with an average relative humidity of 82%.

In Winnetka, the average relative humidity in January is 82%.

In Winnetka, in January, during 7.3 rainfall days, 1.77" (45mm) of precipitation is typically accumulated.

The month with the most snowfall is January, when snow falls for 13.1 days and typically aggregates up to 4.84" (123mm) of snow.

In Winnetka, in January, snow falls for 13.1 days, with typically accumulated 4.84" (123mm) of snow.

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

In January, on the first day of the month, sunrise is at 7:19 am and sunset at 4:29 pm. On the last day of the month, sunrise is at 7:05 am and sunset at 5:03 pm CST.

The month with the least sunshine is January, with an average of 3.7h of sunshine.

In January, the average sunshine duration is 3.7h.

In January, the average daily maximum UV index is 2. A UV Index of 2, and less, symbolizes a low health risk from unsafe exposure to Sun's UV rays.
Average high temperature
Average low temperature
Average pressure
Average wind speed
Average max. wind speed
Average wind speed gusts
Average humidity
Average rainfall
Average rainfall days
Average snowfall
Average snowfall days
Average sunshine
Average sunshine days
Average UV index
Average cloud cover
Average visibility

Average temperature in January
Winnetka, IL

  • Average high temperature in January: 28.8°F

The warmest month (with the highest average high temperature) is July (79.2°F).
The month with the lowest average high temperature is January (28.8°F).

  • Average low temperature in January: 18.9°F

The month with the highest average low temperature is July (67.1°F).
The coldest month (with the lowest average low temperature) is January (18.9°F).

Average pressure in January
Winnetka, 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).

Average wind speed in January
Winnetka, IL

  • Average wind speed in January: 11.5mph

The windiest month (with the highest average wind speed) is January (11.5mph).
The calmest month (with the lowest average wind speed) is August (7.1mph).

Average humidity in January
Winnetka, IL

  • Average humidity in January: 82%

The month with the highest relative humidity is January (82%).
The month with the lowest relative humidity is October (73%).

Average rainfall in January
Winnetka, IL

  • Average rainfall in January: 1.77"

The wettest months (with the highest rainfall) are May and June (4.57").
The driest month (with the least rainfall) is December (1.65").

Average rainfall days in January
Winnetka, IL

  • Average rainfall days in January: 7.3 days

The month with the highest number of rainy days is May (19.1 days).
The month with the least rainy days is February (6.1 days).

Average snowfall in January
Winnetka, IL

  • Average snowfall in January: 4.84"

The month with the highest snowfall is January (4.84").
The months with the least snowfall are June, July, August and September (0").

Average snowfall days in January
Winnetka, IL

  • Average snowfall days in January: 13.1 days

The month with the highest number of snowfall days is January (13.1 days).
The months with the least snowfall days are June, July, August and September (0 days).

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

  • Average daylight in January: 9h and 30min

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 42min

The months with the most sunshine are July and August (Average sunshine: 10h and 24min).
The month with the least sunshine is January (Average sunshine: 3h and 42min).

Average sunshine days in January
Winnetka, IL

  • Average sunshine days in January: 11.8 days

The month with the most sunshine days is November (15.5 days).
The month with the least sunshine days is June (9.2 days).

Average UV index in January
Winnetka, IL

  • Average UV index in January: 2

The months with the highest UV index are June, July and August (UV index 6).
The month with the lowest UV index is December (UV index 1).

Average cloud cover in January
Winnetka, IL

  • Average cloud cover in January: 61

The month with the most cloud cover is January (Cloud cover 61).
The months with the least cloud cover are July and August (Cloud cover 28).

Average visibility in January
Winnetka, IL

  • Average visibility in January: 6mi

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