January weather forecast
Joliet, IL

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A unique shot of cars, trees, and buildings along a street in the town of Joliet, Illinois
A unique shot of cars, trees, and buildings along a street in the town of Joliet, Illinois

Weather in January

The climate in Joliet, Illinois in January manifests the heart of winter characterized by its relative coldness and dampness. This month sees the maximum snowfall with 4.33" (110mm) and registers an average high of 29.3°F (-1.5°C) and a low of 17.4°F (-8.1°C), enumerating the lowest temperatures of the year. Limited sunlight can be expected with short, frost-filled days and prolonged nights, along with the dominance of high relative humidity. Flurries and gusty winds are frequent phenomenon, and a higher percentage of cloud cover is also observed.

Temperature

With an average high-temperature of 29.3°F (-1.5°C) and an average low-temperature of 17.4°F (-8.1°C), January is the coldest month.

Humidity

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

Rainfall

In Joliet, in January, it is raining for 6.8 days, with typically 1.85" (47mm) of accumulated precipitation. In Joliet, during the entire year, the rain falls for 153.6 days and collects up to 32.72" (831mm) of precipitation.

Snowfall

Months with snowfall are January through April, November and December. The month with the most snowfall is January, when snow falls for 11.9 days and typically aggregates up to 4.33" (110mm) of snow.

Daylight

In January, the average length of the day is 9h and 35min.
On the first day of the month, sunrise is at 7:18 am and sunset at 4:32 pm. On the last day of January, sunrise is at 7:05 am and sunset at 5:06 pm CST.

Sunshine

January has the least sunshine of the year, with an average of 3.7h 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 low health risk from unprotected exposure to Sun's UV rays for average individuals.
Note: A maximum UV index of 1 in January translates into the following recommendations:
Babies, children, and those with sensitive skin should always avoid extended periods in the sun. The Sun's most harmful UV rays are emitted around midday; avoid staying outdoors for long during this time. For minimizing sun-related eye damage, always choose sunglasses with UVA and UVB coverage. On your guard! Snow's reflection can almost double the intensity of the Sun's UV radiation.
Updated: Aug 15, 2024
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate

Frequently asked questions

What month is the coldest?

January tends to be the coldest month, with temperatures averaging a daily high of 29.3°F (-1.5°C) and a low of 17.4°F (-8.1°C).

How cold is January?

The high-temperature, in January, in Joliet, is 29.3°F (-1.5°C), while the low-temperature averages to 17.4°F (-8.1°C).

What is the average humidity in January?

The average relative humidity in January is 82%.

How many days does it rain in January?

In Joliet, in January, it is raining for 6.8 days, with typically 1.85" (47mm) of accumulated precipitation.

When does it snow the most?

The month with the most snowfall is January, when snow falls for 11.9 days and typically aggregates up to 4.33" (110mm) of snow.

How much does it snow in January?

In January, it is snowing for 11.9 days. Throughout January, 4.33" (110mm) of snow is accumulated.

What is the average length of the day in January?

In Joliet, the average day length in January is 9h and 35min.

What time are sunrise and sunset in January?

On the first day of January, sunrise is at 7:18 am and sunset at 4:32 pm. On the last day of the month, sunrise is at 7:05 am and sunset at 5:06 pm CST.

What is the month with the least sunshine in Joliet?

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

How many hours of sunshine does Joliet have in January?

In January, the average sunshine duration is 3.7h.

What are the months with the lowest UV index?

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

What is the UV index intensity in January in Joliet?

In January, the average daily maximum UV index is 1. A UV Index of 2, and less, symbolizes a minimal hazard to health from exposure to Sun's UV rays.
Average humidity
Average rainfall days
Average snowfall days
Average daylight
Average sunshine
Average sunshine days
Average UV index
Average cloud cover
Average visibility

Average temperature in January
Joliet, IL

Average temperature in January - Joliet, IL
  • Average high temperature in January: 29.3°F

The warmest month (with the highest average high temperature) is July (81.3°F).
The month with the lowest average high temperature is January (29.3°F).

  • Average low temperature in January: 17.4°F

The month with the highest average low temperature is July (64.8°F).
The coldest month (with the lowest average low temperature) is January (17.4°F).

Average pressure in January
Joliet, IL

Average pressure in January - Joliet, IL
  • Average pressure in January: 30.12"Hg

The month with the highest atmospheric pressure is January (30.12"Hg).
The month with the lowest atmospheric pressure is June (29.92"Hg).

Average wind speed in January
Joliet, IL

Average wind speed in January - Joliet, IL
  • Average wind speed in January: 9.5mph

The windiest month (with the highest average wind speed) is April (9.7mph).
The calmest month (with the lowest average wind speed) is August (5.9mph).

Average humidity in January
Joliet, IL

Average humidity in January - Joliet, IL
  • Average humidity in January: 82%

The month with the highest relative humidity is February (83%).
The month with the lowest relative humidity is October (73%).

Average rainfall in January
Joliet, IL

Average rainfall in January - Joliet, IL
  • Average rainfall in January: 1.85"

The wettest month (with the highest rainfall) is May (4.41").
The driest month (with the least rainfall) is February (1.61").

Average rainfall days in January
Joliet, IL

Average rainfall days in January - Joliet, IL
  • Average rainfall days in January: 6.8 days

The month with the highest number of rainy days is July (17.9 days).
The month with the least rainy days is February (5.7 days).

Average snowfall in January
Joliet, IL

Average snowfall in January - Joliet, IL
  • Average snowfall in January: 4.33"

The month with the highest snowfall is January (4.33").
The months with the least snowfall are May, June, July, August, September and October (0").

Average snowfall days in January
Joliet, IL

Average snowfall days in January - Joliet, IL
  • Average snowfall days in January: 11.9 days

The month with the highest number of snowfall days is January (11.9 days).
The months with the least snowfall days are May, June, July, August and September (0 days).

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

Average daylight in January / Average sunshine in January - Joliet, IL
  • Average daylight in January: 9h and 4min

The month with the longest days is June (Average daylight: 15h and 6min).
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 August (Average sunshine: 9h and 42min).
The month with the least sunshine is January (Average sunshine: 3h and 42min).

Average sunshine days in January
Joliet, IL

Average sunshine days in January - Joliet, IL
  • Average sunshine days in January: 14.4 days

The month with the most sunshine days is November (18.1 days).
The month with the least sunshine days is June (10.4 days).

Average UV index in January
Joliet, IL

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

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

Average cloud cover in January
Joliet, IL

Average cloud cover in January - Joliet, IL
  • Average cloud cover in January: 60

The month with the most cloud cover is January (Cloud cover 60).
The months with the least cloud cover are August and September (Cloud cover 34).

Average visibility in January
Joliet, IL

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

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

Joliet, Illinois, USA

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