Contents
- Weather in January
- Frequently asked questions
- Average temperature in January
- Average pressure in January
- Average wind speed in January
- Average humidity in January
- Average rainfall in January
- Average rainfall days in January
- Average snowfall in January
- Average snowfall days in January
- Average daylight in January
- Average sunshine in January
- Average sunshine days in January
- Average UV index in January
- Average cloud cover in January
- Average visibility in January
Weather in January
Temperature
The coldest period tends to be January, when average temperatures fluctuate between a high of 36°F (2.2°C) and a low of 23.9°F (-4.5°C).Humidity
In January, the average relative humidity is 75%.Rainfall
In January, the rain falls for 9.5 days. Throughout January, 1.97" (50mm) of precipitation is accumulated. Throughout the year, there are 160.7 rainfall days, and 30.12" (765mm) of precipitation is accumulated.Snowfall
Months with snowfall are January through May, October through December. In Mountainside, in January, during 7.3 snowfall days, 2.09" (53mm) of snow is typically accumulated. In Mountainside, during the entire year, snow falls for 25.4 days and aggregates up to 10.31" (262mm) of snow.Daylight
In Mountainside, New Jersey, the average length of the day in January is 9h and 40min.On the first day of the month, sunrise is at 7:21 am and sunset at 4:40 pm. On the last day of January, sunrise is at 7:08 am and sunset at 5:13 pm EST.
Sunshine
In Mountainside, the average sunshine in January is 5.1h.UV index
The months with the lowest UV index are January through March, November and December, with an average maximum UV index of 2. A UV Index of 2, and less, symbolizes a minimal health hazard from unprotected exposure to Sun's UV rays for the average person.Note: The maximum daily UV index of 2 in January converts into the following recommendations:
Children, babies, and those with sensitive skin should always be shielded from long periods of sun exposure. Exposing oneself to the midday Sun can be harmful due to the strong UV radiation; limit your time outside. Loose clothes with a tight weave are optimal for safeguarding yourself against the Sun's rays. Take warning! The intensity of the Sun's UV radiation can be nearly amplified twice due to snow reflection.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
What month is the coldest?
How cold is it in January?
What is the average humidity in January?
How many days does it rain in January?
How much does it snow in January?
How many hours of daylight does Mountainside have in January?
When are sunrise and sunset in January?
How long on average sun shines in January in Mountainside?
What are the months with the lowest UV index?
What is the UV index reading in January?
Average temperature in January
Mountainside, NJ
- Average high temperature in January: 36°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 (36°F).
- Average low temperature in January: 23.9°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 (23.9°F).
Average pressure in January
Mountainside, NJ
- Average pressure in January: 30.07"Hg
The month with the highest atmospheric pressure is November (30.11"Hg).
The month with the lowest atmospheric pressure is June (29.93"Hg).
Average wind speed in January
Mountainside, NJ
- Average wind speed in January: 8.8mph
The windiest month (with the highest average wind speed) is March (8.9mph).
The calmest months (with the lowest average wind speed) are July and August (5.7mph).
Average humidity in January
Mountainside, NJ
- Average humidity in January: 75%
The months with the highest relative humidity are February, October and December (78%).
The months with the lowest relative humidity are April and August (73%).
Average rainfall in January
Mountainside, NJ
- Average rainfall in January: 1.97"
The wettest month (with the highest rainfall) is December (3.19").
The driest month (with the least rainfall) is September (1.69").
Average rainfall days in January
Mountainside, NJ
- Average rainfall days in January: 9.5 days
The month with the highest number of rainy days is July (16.5 days).
The month with the least rainy days is January (9.5 days).
Average snowfall in January
Mountainside, NJ
- Average snowfall in January: 2.09"
The month with the highest snowfall is March (3.23").
The months with the least snowfall are June, July, August and September (0").
Average snowfall days in January
Mountainside, NJ
- Average snowfall days in January: 7.3 days
The months with the highest number of snowfall days are January and February (7.3 days).
The months with the least snowfall days are June, July, August and September (0 days).
Average daylight in January /
Average sunshine in January
Mountainside, NJ
- Average daylight in January: 9h and 4min
The month with the longest days is June (Average daylight: 15h and 0min).
The month with the shortest days is December (Average daylight: 9h and 18min).
- Average sunshine in January: 5h and 1min
The month with the most sunshine is July (Average sunshine: 10h and 30min).
The month with the least sunshine is February (Average sunshine: 4h and 36min).
Average sunshine days in January
Mountainside, NJ
- Average sunshine days in January: 17.3 days
The month with the most sunshine days is November (18.4 days).
The month with the least sunshine days is June (11.4 days).
Average UV index in January
Mountainside, NJ
- 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, March, November and December (UV index 2).
Average cloud cover in January
Mountainside, NJ
- Average cloud cover in January: 45
The months with the most cloud cover are February, March and December (Cloud cover 48).
The months with the least cloud cover are July and August (Cloud cover 32).
Average visibility in January
Mountainside, NJ
- Average visibility in January: 6mi
The months with the highest visibility are January, February, March, April, June, July, August, September, October, November and December (6mi).
The month with the lowest visibility is May (5mi).
Mountainside, New Jersey, USA
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