January weather forecast
Williamson, IL

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Weather in January

January, like December, in Williamson, Illinois, is another cold winter month, with an average temperature ranging between min 22.6°F (-5.2°C) and max 35.6°F (2°C).

Temperature

In Williamson, the lowest temperatures are generally noted in January, averaging a high of 35.6°F (2°C) and a low of 22.6°F (-5.2°C).

Humidity

The average relative humidity in January in Williamson is 77%.

Rainfall

In January, in Williamson, Illinois, the rain falls for 5.8 days. Throughout January, 1.02" (26mm) of precipitation is accumulated. In Williamson, during the entire year, the rain falls for 121.4 days and collects up to 14.72" (374mm) of precipitation.

Snowfall

January through March, November and December are months with snowfall in Williamson. In Williamson, in January, snow falls for 6.3 days, with typically accumulated 0.63" (16mm) of snow. In Williamson, during the entire year, snow falls for 19.8 days and aggregates up to 2.91" (74mm) of snow.

Daylight

The average length of the day in January is 9h and 48min.
On the first day of the month, sunrise is at 7:17 am and sunset at 4:47 pm. On the last day of January, sunrise is at 7:06 am and sunset at 5:18 pm CST.

Sunshine

With an average of 4.4h of sunshine, January has the least sunshine of the year in Williamson.

UV index

The months with the lowest UV index are January, February, November and December, with an average maximum UV index of 2. A UV Index value of 2, and less, symbolizes a low threat to health from exposure to the Sun's UV radiation for ordinary individuals.
Note: A maximum daily UV index of 2 during January morphs into the following directions:
Though the majority can handle prolonged sun exposure, it is crucial to always shield babies, children, and those with fair skin. The intensity of the Sun's UV radiation during midday suggests reducing time spent outdoors. Outfit yourself in sun-safe attire, like long sleeves, pants, a hat, and UV-blocking sunglasses. Be attentive! The reflective property of snow can nearly double the Sun's UV radiation.
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Frequently asked questions

What month is the coldest in Williamson?

In Williamson, January registers the lowest temperatures, averaging 35.6°F (2°C) at the peak and 22.6°F (-5.2°C) at the lowest.

How cold is January in Williamson?

In January, in Williamson, the average high-temperature is 35.6°F (2°C), and the average low-temperature is 22.6°F (-5.2°C).

What is the average humidity in January in Williamson?

In January, the average relative humidity in Williamson is 77%.

How much does it rain in Williamson in January?

In Williamson, in January, during 5.8 rainfall days, 1.02" (26mm) of precipitation is typically accumulated.

How many days does it snow in January in Williamson?

In Williamson, in January, snow falls for 6.3 days, with typically accumulated 0.63" (16mm) of snow.

How many hours of daylight does Williamson have in January?

The average day length in January in Williamson, Illinois, is 9h and 48min.

When are sunrise and sunset in January in Williamson?

On the first day of January in Williamson, Illinois, sunrise is at 7:17 am and sunset at 4:47 pm. On the last day of the month, sunrise is at 7:06 am and sunset at 5:18 pm CST.

What is the month with the least sunshine in Williamson?

With an average of 4.4h of sunshine, January has the least sunshine of the year.

How many hours of sunshine does Williamson have in January?

The average sunshine duration in January is 4.4h.

What are the months with the lowest UV index in Williamson?

The months with the lowest UV index in Williamson are January, February, November and December, with an average maximum UV index of 2.

What is the UV index intensity in January in Williamson?

In Williamson, the average daily maximum UV index in January is 2. A UV Index reading of 2, and below, represents a low health threat 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
Williamson, IL

Average temperature in January - Williamson, IL
  • Average high temperature in January: 35.6°F

The warmest month (with the highest average high temperature) is July (84.2°F).
The month with the lowest average high temperature is January (35.6°F).

  • Average low temperature in January: 22.6°F

The month with the highest average low temperature is July (67.5°F).
The coldest month (with the lowest average low temperature) is January (22.6°F).

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Average pressure in January
Williamson, IL

Average pressure in January - Williamson, IL
  • Average pressure in January: 30.16"Hg

The month with the highest atmospheric pressure is January (30.16"Hg).
The month with the lowest atmospheric pressure is June (29.92"Hg).

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Average wind speed in January
Williamson, IL

Average wind speed in January - Williamson, IL
  • Average wind speed in January: 10mph

The windiest month (with the highest average wind speed) is January (10mph).
The calmest month (with the lowest average wind speed) is July (5.8mph).

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Average humidity in January
Williamson, IL

Average humidity in January - Williamson, IL
  • Average humidity in January: 77%

The month with the highest relative humidity is July (81%).
The month with the lowest relative humidity is October (71%).

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Average rainfall in January
Williamson, IL

Average rainfall in January - Williamson, IL
  • Average rainfall in January: 1.02"

The wettest month (with the highest rainfall) is June (1.89").
The driest month (with the least rainfall) is February (0.67").

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Average rainfall days in January
Williamson, IL

Average rainfall days in January - Williamson, IL
  • Average rainfall days in January: 5.8 days

The month with the highest number of rainy days is July (14 days).
The month with the least rainy days is January (5.8 days).

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Average snowfall in January
Williamson, IL

Average snowfall in January - Williamson, IL
  • Average snowfall in January: 0.63"

The month with the highest snowfall is December (0.98").
The months with the least snowfall are April, May, June, July, August, September and October (0").

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Average snowfall days in January
Williamson, IL

Average snowfall days in January - Williamson, IL
  • Average snowfall days in January: 6.3 days

The month with the highest number of snowfall days is January (6.3 days).
The months with the least snowfall days are May, June, July, August and September (0 days).

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

Average daylight in January / Average sunshine in January - Williamson, IL
  • Average daylight in January: 9h and 5min

The month with the longest days is June (Average daylight: 14h and 54min).
The month with the shortest days is December (Average daylight: 9h and 30min).

  • Average sunshine in January: 4h and 2min

The months with the most sunshine are June and July (Average sunshine: 10h and 18min).
The month with the least sunshine is January (Average sunshine: 4h and 24min).

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Average sunshine days in January
Williamson, IL

Average sunshine days in January - Williamson, IL
  • Average sunshine days in January: 20.9 days

The month with the most sunshine days is January (20.9 days).
The month with the least sunshine days is July (12.5 days).

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Average UV index in January
Williamson, IL

Average UV index in January - Williamson, IL
  • Average UV index in January: 2

The months with the highest UV index are June, July and August (UV index 6).
The months with the lowest UV index are January, February, November and December (UV index 2).

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Average cloud cover in January
Williamson, IL

Average cloud cover in January - Williamson, IL
  • Average cloud cover in January: 52

The month with the most cloud cover is January (Cloud cover 52).
The months with the least cloud cover are June, July, August and September (Cloud cover 29).

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Average visibility in January
Williamson, IL

Average visibility in January - Williamson, 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).

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Williamson, Illinois, USA

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