January weather forecast
Williamstown, NJ

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Weather in January

January, the same as December, is an icy winter month in Williamstown, New Jersey, with an average temperature varying between 38.1°F (3.4°C) and 26.8°F (-2.9°C).

Temperature

January, with its high-temperature average of 38.1°F (3.4°C) and a low-temperature average of 26.8°F (-2.9°C), is the coldest month.

Humidity

In January, the average relative humidity in Williamstown is 74%.

Rainfall

In January, in Williamstown, the rain falls for 8.8 days. Throughout January, 2.09" (53mm) of precipitation is accumulated. Throughout the year, in Williamstown, there are 154.9 rainfall days, and 30.47" (774mm) of precipitation is accumulated.

Snowfall

Months with snowfall are January through May, November and December. In January, in Williamstown, New Jersey, it is snowing for 5.5 days. Throughout January, 2.4" (61mm) of snow is accumulated. In Williamstown, during the entire year, snow falls for 17.8 days and aggregates up to 10.28" (261mm) of snow.

Daylight

In January, the average length of the day in Williamstown is 9h and 44min.
On the first day of the month, sunrise is at 7:20 am and sunset at 4:46 pm. On the last day of January, sunrise is at 7:08 am and sunset at 5:17 pm EST.

Sunshine

In January, the average sunshine is 5.1h.

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 health risk from exposure to the Sun's UV rays for the ordinary person.
Note: In January, the average maximum UV index of 2 translates into the following recommendations:
Unlike children, who always need sun protection, most individuals can remain in the sun for up to an hour without getting burnt. UV radiation is strongest from the Sun during midday; protect yourself by staying in shaded areas. To mitigate harm from sun exposure, pick sunglasses offering UVA and UVB defense. Be alert! Nearly double the UV rays from the Sun can be reflected by snow.
Updated: Feb 13, 2024
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate

Frequently asked questions

What month is the coldest in Williamstown?

Williamstown's coldest temperatures are experienced in January, with average high temperatures of 38.1°F (3.4°C) and lows of 26.8°F (-2.9°C).

How cold does it get in Williamstown in January?

The average high-temperature, in January, in Williamstown, is 38.1°F (3.4°C), while the average low-temperature is 26.8°F (-2.9°C).

What is the average humidity in January in Williamstown?

In January, the average relative humidity is 74%.

How many days does it rain in January in Williamstown?

In Williamstown, in January, it is raining for 8.8 days, with typically 2.09" (53mm) of accumulated precipitation.

How much does it snow in Williamstown in January?

In Williamstown, New Jersey, in January, snow falls for 5.5 days, with typically accumulated 2.4" (61mm) of snow.

How many hours of daylight does Williamstown have in January?

The average day length in January in Williamstown is 9h and 44min.

When are sunrise and sunset in January in Williamstown?

In January, on the first day of the month, sunrise is at 7:20 am and sunset at 4:46 pm. On the last day of the month, in Williamstown, sunrise is at 7:08 am and sunset at 5:17 pm EST.

How many hours of sunshine does Williamstown have in January?

In January, the average sunshine duration in Williamstown is 5.1h.

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

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

How high is the UV index in January in Williamstown?

In Williamstown, the average daily maximum UV index in January is 2. A UV Index of 2, and less, symbolizes a minimal hazard to health 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
Williamstown, NJ

Average temperature in January - Williamstown, NJ
  • Average high temperature in January: 38.1°F

The warmest month (with the highest average high temperature) is July (85.3°F).
The month with the lowest average high temperature is January (38.1°F).

  • Average low temperature in January: 26.8°F

The month with the highest average low temperature is July (68.5°F).
The coldest month (with the lowest average low temperature) is January (26.8°F).

Average pressure in January
Williamstown, NJ

Average pressure in January - Williamstown, NJ
  • Average pressure in January: 30.09"Hg

The month with the highest atmospheric pressure is November (30.12"Hg).
The month with the lowest atmospheric pressure is June (29.94"Hg).

Average wind speed in January
Williamstown, NJ

Average wind speed in January - Williamstown, NJ
  • Average wind speed in January: 8.4mph

The windiest month (with the highest average wind speed) is April (8.7mph).
The calmest month (with the lowest average wind speed) is August (5.7mph).

Average humidity in January
Williamstown, NJ

Average humidity in January - Williamstown, NJ
  • Average humidity in January: 74%

The month with the highest relative humidity is October (78%).
The month with the lowest relative humidity is April (71%).

Average rainfall in January
Williamstown, NJ

Average rainfall in January - Williamstown, NJ
  • Average rainfall in January: 2.09"

The wettest month (with the highest rainfall) is December (3.35").
The driest month (with the least rainfall) is September (1.73").

Average rainfall days in January
Williamstown, NJ

Average rainfall days in January - Williamstown, NJ
  • Average rainfall days in January: 8.8 days

The month with the highest number of rainy days is July (16.9 days).
The month with the least rainy days is January (8.8 days).

Average snowfall in January
Williamstown, NJ

Average snowfall in January - Williamstown, NJ
  • Average snowfall in January: 2.4"

The month with the highest snowfall is March (3.54").
The months with the least snowfall are June, July, August, September and October (0").

Average snowfall days in January
Williamstown, NJ

Average snowfall days in January - Williamstown, NJ
  • Average snowfall days in January: 5.5 days

The month with the highest number of snowfall days is January (5.5 days).
The months with the least snowfall days are June, July, August, September and October (0 days).

Average daylight in January /
Average sunshine in January
Williamstown, NJ

Average daylight in January / Average sunshine in January - Williamstown, NJ
  • Average daylight in January: 9h and 4min

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 24min).

  • Average sunshine in January: 5h and 1min

The month with the most sunshine is July (Average sunshine: 10h and 48min).
The month with the least sunshine is February (Average sunshine: 4h and 54min).

Average sunshine days in January
Williamstown, NJ

Average sunshine days in January - Williamstown, NJ
  • Average sunshine days in January: 18.2 days

The month with the most sunshine days is November (19.5 days).
The month with the least sunshine days is July (11.8 days).

Average UV index in January
Williamstown, NJ

Average UV index in January - Williamstown, NJ
  • Average UV index in January: 2

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

Average cloud cover in January
Williamstown, NJ

Average cloud cover in January - Williamstown, NJ
  • Average cloud cover in January: 44

The months with the most cloud cover are February and March (Cloud cover 46).
The months with the least cloud cover are July and August (Cloud cover 30).

Average visibility in January
Williamstown, NJ

Average visibility in January - Williamstown, NJ
  • 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).

Williamstown, New Jersey, USA

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