Contents
- Weather in December
- Frequently asked questions
- Average temperature in December
- Average pressure in December
- Average wind speed in December
- Average humidity in December
- Average rainfall in December
- Average rainfall days in December
- Average snowfall in December
- Average snowfall days in December
- Average daylight in December
- Average sunshine in December
- Average sunshine days in December
- Average UV index in December
- Average cloud cover in December
- Average visibility in December
Weather in December
Temperature
The transition into December is accompanied by a temperature decrease, with the average high-temperature shifting from a cool 50.4°F (10.2°C) in November to an icy 41°F (5°C). Nighttime temperature lowers to an average of 29.3°F (-1.5°C) in December.Humidity
The average relative humidity in December is 79%.Rainfall
The month with the most rainfall in Mendham is December, when the rain falls for 10.9 days and typically aggregates up to 3.39" (86mm) of precipitation.Snowfall
Months with snowfall are January through May, October through December. In December, it is snowing for 4 days. Throughout December, 2.13" (54mm) of snow is accumulated. Throughout the year, there are 28.5 snowfall days, and 14.49" (368mm) of snow is accumulated.Daylight
With an average of 9h and 18min of daylight, December has the shortest days of the year.On the first day of December, sunrise is at 7:03 am and sunset at 4:31 pm. On the last day of the month, sunrise is at 7:22 am and sunset at 4:40 pm EST.
Sunshine
In Mendham, the average sunshine in December is 4.8h.UV index
January through March, November and December, with an average maximum UV index of 2, are months with the lowest UV index in Mendham. A UV Index reading of 2, and below, represents a minimal health vulnerability from exposure to the Sun's UV radiation for the ordinary person.Note: In December, the average maximum UV index of 2 translates into the following recommendations:
Sun exposure does not present considerable issues for many, yet infants, fair-skinned people, and children necessitate constant protection. Avoiding direct sunlight during midday hours helps reduce the risk from intense UV radiation. To mitigate harm from sun exposure, pick sunglasses offering UVA and UVB defense. Be watchful! The reflection of snow can enhance the intensity of the Sun's UV radiation nearly double.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
How cold is December?
What is the average humidity in December?
What is the wettest month?
How much does it rain in December?
How much does it snow in Mendham in December?
What is the month with the shortest days?
How many hours of daylight does Mendham have in December?
What time are sunrise and sunset in December?
How long on average sun shines in December?
What are the months with the lowest UV index?
What is the UV index reading in December?
Average temperature in December
Mendham, NJ
- Average high temperature in December: 41°F
The warmest month (with the highest average high temperature) is July (83.7°F).
The month with the lowest average high temperature is January (35.1°F).
- Average low temperature in December: 29.3°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 (22.3°F).
Average pressure in December
Mendham, NJ
- Average pressure in December: 30.08"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 December
Mendham, NJ
- Average wind speed in December: 7.5mph
The windiest month (with the highest average wind speed) is March (8.3mph).
The calmest month (with the lowest average wind speed) is August (5.1mph).
Average humidity in December
Mendham, NJ
- Average humidity in December: 79%
The months with the highest relative humidity are February and October (80%).
The month with the lowest relative humidity is April (75%).
Average rainfall in December
Mendham, NJ
- Average rainfall in December: 3.39"
The wettest month (with the highest rainfall) is December (3.39").
The driest month (with the least rainfall) is September (1.85").
Average rainfall days in December
Mendham, NJ
- Average rainfall days in December: 10.9 days
The months with the highest number of rainy days are May and July (17.3 days).
The month with the least rainy days is January (8.9 days).
Average snowfall in December
Mendham, NJ
- Average snowfall in December: 2.13"
The month with the highest snowfall is March (4.49").
The months with the least snowfall are June, July, August and September (0").
Average snowfall days in December
Mendham, NJ
- Average snowfall days in December: 4 days
The month with the highest number of snowfall days is January (8.3 days).
The months with the least snowfall days are June, July, August and September (0 days).
Average daylight in December /
Average sunshine in December
Mendham, NJ
- Average daylight in December: 9h and 2min
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 18min).
- Average sunshine in December: 4h and 5min
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 December
Mendham, NJ
- Average sunshine days in December: 16.6 days
The month with the most sunshine days is November (17.6 days).
The month with the least sunshine days is May (11.4 days).
Average UV index in December
Mendham, NJ
- Average UV index in December: 2
The months with the highest UV index are June and July (UV index 6).
The months with the lowest UV index are January, February, March, November and December (UV index 2).
Average cloud cover in December
Mendham, NJ
- Average cloud cover in December: 49
The months with the most cloud cover are February and December (Cloud cover 49).
The month with the least cloud cover is July (Cloud cover 33).
Average visibility in December
Mendham, NJ
- Average visibility in December: 6mi
The months with the highest visibility are January, February, March, April, June, July, August, November and December (6mi).
The months with the lowest visibility are May, September and October (5mi).
Mendham, New Jersey, USA
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