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
A decrease in the average high-temperature is observed during December, shifting from a fresh 50°F (10°C) in November to a wintry 40.3°F (4.6°C). In December, the average low-temperature records at a freezing cold 28.9°F (-1.7°C) during the nights.Humidity
In Mount Joy, the average relative humidity in December is 80%.Rainfall
In Mount Joy, in December, during 8.5 rainfall days, 1.1" (28mm) of precipitation is typically accumulated. Throughout the year, in Mount Joy, there are 124.4 rainfall days, and 13.39" (340mm) of precipitation is accumulated.Snowfall
January through April, November and December are months with snowfall. In December, it is snowing for 3.3 days. Throughout December, 1.1" (28mm) of snow is accumulated. Throughout the year, there are 22 snowfall days, and 5" (127mm) of snow is accumulated.Daylight
December has the shortest days of the year, with an average of 9h and 18min of daylight.On the first day of December, sunrise is at 7:05 am and sunset at 4:34 pm. On the last day of the month, sunrise is at 7:24 am and sunset at 4:43 pm EST.
Sunshine
In Mount Joy, the average sunshine in December is 4.8h.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 estimate of 2, and below, represents a low threat to health from exposure to the Sun's UV rays for the ordinary person.Note: The UV index of 2 during December translates into the following guidance:
Despite the majority tolerating prolonged sun exposure, those with sensitive skin, infants, and children demand continual protection. For skin protection, it's recommended to minimize Sun exposure during its peak hours around midday. Safeguard your eyes, ears, and face from sun rays with the aid of a wide-brim hat. Take into account! The reflection from snow can nearly double the Sun's UV radiation intensity.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
How cold is it in December?
What is the average humidity in December?
How many days does it rain in December in Mount Joy?
How much does it snow in December?
What is the month with the shortest days?
What is the average length of the day in December?
What time are sunrise and sunset in December in Mount Joy?
How many hours of sunshine does Mount Joy have in December?
When is the lowest UV index?
How high is the UV index in December?
Average temperature in December
Mount Joy, NJ
- Average high temperature in December: 40.3°F
The warmest month (with the highest average high temperature) is July (83.3°F).
The month with the lowest average high temperature is January (34.3°F).
- Average low temperature in December: 28.9°F
The month with the highest average low temperature is July (63.9°F).
The coldest month (with the lowest average low temperature) is January (21.6°F).
Average pressure in December
Mount Joy, NJ
- Average pressure in December: 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 December
Mount Joy, NJ
- Average wind speed in December: 7.5mph
The windiest month (with the highest average wind speed) is March (8.1mph).
The calmest month (with the lowest average wind speed) is August (4.9mph).
Average humidity in December
Mount Joy, NJ
- Average humidity in December: 80%
The month with the highest relative humidity is February (81%).
The months with the lowest relative humidity are April and July (76%).
Average rainfall in December
Mount Joy, NJ
- Average rainfall in December: 1.1"
The wettest month (with the highest rainfall) is July (1.65").
The driest month (with the least rainfall) is September (0.71").
Average rainfall days in December
Mount Joy, NJ
- Average rainfall days in December: 8.5 days
The month with the highest number of rainy days is May (13.9 days).
The month with the least rainy days is January (7.1 days).
Average snowfall in December
Mount Joy, NJ
- Average snowfall in December: 1.1"
The month with the highest snowfall is February (1.42").
The months with the least snowfall are May, June, July, August, September and October (0").
Average snowfall days in December
Mount Joy, NJ
- Average snowfall days in December: 3.3 days
The month with the highest number of snowfall days is February (6.8 days).
The months with the least snowfall days are May, June, July, August, September and October (0 days).
Average daylight in December /
Average sunshine in December
Mount Joy, NJ
- Average daylight in December: 9h and 2min
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 December: 4h and 5min
The month with the most sunshine is July (Average sunshine: 10h and 24min).
The month with the least sunshine is February (Average sunshine: 4h and 36min).
Average sunshine days in December
Mount Joy, NJ
- Average sunshine days in December: 19.8 days
The month with the most sunshine days is November (20.2 days).
The month with the least sunshine days is May (14 days).
Average UV index in December
Mount Joy, 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
Mount Joy, NJ
- Average cloud cover in December: 49
The month with the most cloud cover is February (Cloud cover 50).
The month with the least cloud cover is July (Cloud cover 34).
Average visibility in December
Mount Joy, NJ
- Average visibility in December: 6mi
The months with the highest visibility are January, March, April, November and December (6mi).
The months with the lowest visibility are February, May, June, July, August, September and October (5mi).
Mount Joy, New Jersey, USA
Weather forecast for your location
2. Allow the app to use your location