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
In Mount Joy, entering December brings a temperature decrement, reducing from November's cool 50°F (10°C) to an icy 40.3°F (4.6°C). The low-temperature average for Mount Joy during December stands at a subzero cold 28.9°F (-1.7°C).Humidity
The average relative humidity in December is 80%.Rainfall
In December, the rain falls for 8.5 days. Throughout December, 1.1" (28mm) of precipitation is accumulated. Throughout the year, 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 Mount Joy. In Mount Joy, in December, during 3.3 snowfall days, 1.1" (28mm) of snow is typically accumulated. Throughout the year, in Mount Joy, there are 22 snowfall days, and 5" (127mm) of snow is accumulated.Daylight
The month with the shortest days is December, 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 December, the average sunshine 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. A UV Index estimate of 2, and below, represents a low health risk from exposure to the Sun's UV rays for the average person.Note: The daily maximum UV index of 2 in December interprets into the following advice:
Children, infants, and individuals with sensitive skin should be constantly protected from extended sun exposure. The Sun's UV radiation is especially harmful around midday, so reduce exposure and stay safe. Employ a hat with a wide brim for robust protection, cutting UV exposure by half. Take note! UV radiation from the Sun can double in intensity due to snow reflection.
Frequently asked questions
How cold is it in Mount Joy in December?
What is the average humidity in December in Mount Joy?
How many days does it rain in December in Mount Joy?
How many days does it snow in December in Mount Joy?
What is the month with the shortest days in Mount Joy?
What is the average length of the day in December in Mount Joy?
When are sunrise and sunset in December in Mount Joy?
How long on average sun shines in December in Mount Joy?
When is the lowest UV index in Mount Joy?
How high is the UV index in December in Mount Joy?
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
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