January weather forecast
Janesville, WI

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Weather in January

January in Janesville, Wisconsin marks the peak of winter, often showcasing brisk and frosty conditions. Overall, lower than average temperatures dominate this month, which can often lead to a high chance of substantial snowfall. This month significantly tops the other months at 2.83" (72mm) of snowfall on around 12.5 days. It paves the way for a bountiful display of winter scenery across the city. Moving activities indoors and dressing warmly is a must during these chilly weeks.

Temperature

With average high temperatures of 25°F (-3.9°C) and lows of 12.9°F (-10.6°C), January is the coldest month.

Humidity

The most humid month is January, with an average relative humidity of 87%.

Rainfall

January and February are months with the least rain when the rain falls for 3.5 days and typically aggregates up to 0.75" (19mm) of rain.

Snowfall

January through April, October through December are months with snowfall. January is the month with the most snowfall. Snow falls for 12.5 days and accumulates 2.83" (72mm) of snow.

Daylight

In January, the average length of the day is 9h and 28min.
On the first day of the month, sunrise is at 7:26 am and sunset at 4:32 pm. On the last day of January, sunrise is at 7:11 am and sunset at 5:07 pm CST.

Sunshine

With an average of 3.5h of sunshine, January has the least sunshine of the year.

UV index

January and December, with an average maximum UV index of 1, are months with the lowest UV index. A UV Index reading of 2, and below, represents a low health risk from exposure to the Sun's UV radiation for the ordinary person.
Note: In January, the maximum UV index of 1 transforms into these recommendations:
Children must always have sun protection, unlike most people, who can tolerate up to an hour in the sun without any burns. For skin protection, it's recommended to minimize Sun exposure during its peak hours around midday. Using UVA and UVB-protective sunglasses and sun-protective clothing is effective against UV radiation. Take to heart! Snow reflection can almost magnify the Sun's UV radiation twofold.

Frequently asked questions

What is the coldest time of year?

January brings the lowest temperatures in Janesville, Wisconsin, with an average high of 25°F (-3.9°C) and an average low of 12.9°F (-10.6°C).

How cold is January?

An average high-temperature, in January, in Janesville, is 25°F (-3.9°C) and the average low-temperature is 12.9°F (-10.6°C).

What is the most humid month?

The most humid month is January, with an average relative humidity of 87%.

What is the average humidity in January?

In January, the average relative humidity is 87%.

What is the driest month?

January and February are months with the least rain when the rain falls for 3.5 days and typically aggregates up to 0.75" (19mm) of rain.

How many days does it rain in January?

In January, the rain falls for 3.5 days. Throughout January, 0.75" (19mm) of precipitation is accumulated.

When does it snow the most?

The month with the most snowfall is January, when snow falls for 12.5 days and typically aggregates up to 2.83" (72mm) of snow.

How much does it snow in January?

In Janesville, in January, snow falls for 12.5 days, with typically accumulated 2.83" (72mm) of snow.

What is the average length of the day in January?

The average day length in January is 9h and 28min.

When is the sunrise / sunset in January?

On the first day of January, sunrise is at 7:26 am and sunset at 4:32 pm. On the last day of the month, sunrise is at 7:11 am and sunset at 5:07 pm CST.

What is the month with the least sunshine?

With an average of 3.5h of sunshine, January has the least sunshine of the year.

How many hours of sunshine does Janesville have in January?

In Janesville, the average sunshine duration in January is 3.5h.

What are the months with the lowest UV index?

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

How high is the UV index in January?

In Janesville, Wisconsin, the average daily maximum UV index in January is 1. A UV Index of 2, and less, symbolizes a minimal health vulnerability from unsafe 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
Janesville, WI

Average temperature in January - Janesville, WI
  • Average high temperature in January: 25°F

The warmest month (with the highest average high temperature) is July (79.7°F).
The month with the lowest average high temperature is January (25°F).

  • Average low temperature in January: 12.9°F

The month with the highest average low temperature is July (62.4°F).
The coldest month (with the lowest average low temperature) is January (12.9°F).

Average pressure in January
Janesville, WI

Average pressure in January - Janesville, WI
  • 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 (29.91"Hg).

Average wind speed in January
Janesville, WI

Average wind speed in January - Janesville, WI
  • Average wind speed in January: 9.6mph

The windiest month (with the highest average wind speed) is April (10.1mph).
The calmest month (with the lowest average wind speed) is August (6.4mph).

Average humidity in January
Janesville, WI

Average humidity in January - Janesville, WI
  • Average humidity in January: 87%

The month with the highest relative humidity is January (87%).
The months with the lowest relative humidity are April and October (76%).

Average rainfall in January
Janesville, WI

Average rainfall in January - Janesville, WI
  • Average rainfall in January: 0.75"

The wettest month (with the highest rainfall) is June (2.76").
The driest months (with the least rainfall) are January and February (0.75").

Average rainfall days in January
Janesville, WI

Average rainfall days in January - Janesville, WI
  • Average rainfall days in January: 3.5 days

The month with the highest number of rainy days is June (16.3 days).
The month with the least rainy days is January (3.5 days).

Average snowfall in January
Janesville, WI

Average snowfall in January - Janesville, WI
  • Average snowfall in January: 2.83"

The month with the highest snowfall is January (2.83").
The months with the least snowfall are May, June, July, August and September (0").

Average snowfall days in January
Janesville, WI

Average snowfall days in January - Janesville, WI
  • Average snowfall days in January: 12.5 days

The month with the highest number of snowfall days is January (12.5 days).
The months with the least snowfall days are June, July, August and September (0 days).

Average daylight in January /
Average sunshine in January
Janesville, WI

Average daylight in January / Average sunshine in January - Janesville, WI
  • Average daylight in January: 9h and 3min

The month with the longest days is June (Average daylight: 15h and 18min).
The month with the shortest days is December (Average daylight: 9h and 6min).

  • Average sunshine in January: 3h and 3min

The months with the most sunshine are July and August (Average sunshine: 9h and 42min).
The month with the least sunshine is January (Average sunshine: 3h and 30min).

Average sunshine days in January
Janesville, WI

Average sunshine days in January - Janesville, WI
  • Average sunshine days in January: 17.1 days

The month with the most sunshine days is November (19.1 days).
The month with the least sunshine days is June (10.9 days).

Average UV index in January
Janesville, WI

Average UV index in January - Janesville, WI
  • Average UV index in January: 1

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

Average cloud cover in January
Janesville, WI

Average cloud cover in January - Janesville, WI
  • Average cloud cover in January: 64

The month with the most cloud cover is January (Cloud cover 64).
The month with the least cloud cover is September (Cloud cover 34).

Average visibility in January
Janesville, WI

Average visibility in January - Janesville, WI
  • 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).

Janesville, Wisconsin, USA

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