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, the average high-temperature in December drops from a fresh 50.2°F (10.1°C) in November to an icy 41.2°F (5.1°C). In Mount Joy, the average nighttime temperature during December is a subzero cold 30°F (-1.1°C).Humidity
In Mount Joy, the average relative humidity in December is 79%.Rainfall
In Mount Joy, during December, the rain falls for 8.6 days and regularly aggregates up to 1.1" (28mm) of precipitation. Throughout the year, there are 132.7 rainfall days, and 15.35" (390mm) of precipitation is accumulated.Snowfall
January through April, October through December are months with snowfall. In Mount Joy, Pennsylvania, in December, snow falls for 3.4 days, with typically accumulated 0.94" (24mm) of snow. In Mount Joy, during the entire year, snow falls for 19.3 days and aggregates up to 6.5" (165mm) of snow.Daylight
With an average of 9h and 24min of daylight, December has the shortest days of the year.On the first day of the month, sunrise is at 7:09 am and sunset at 4:41 pm. On the last day of December, sunrise is at 7:28 am and sunset at 4:50 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 of 2, and less, symbolizes a minimal health hazard from unprotected exposure to Sun's UV rays for the average person.Note: In December, a daily maximum UV index of 2 leads to the following instructions:
Extended exposure to the sun should always be avoided by children, infants, and those with sensitive skin. The Sun is at its harshest during midday; protect yourself by staying in shaded areas and minimizing exposure. A wide-brimmed hat is a shield, deflecting up to 50% of harmful UV radiation from eyes. Be careful! The Sun's UV radiation can nearly be doubled by the reflective quality of snow.
Frequently asked questions
Is it cold in Mount Joy during December?
What is the average humidity in December in Mount Joy?
How much does it rain in Mount Joy in December?
How much does it snow in Mount Joy in December?
What is the month with the shortest days in Mount Joy?
How many hours of daylight does Mount Joy have in December?
When 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 in Mount Joy?
What is the UV index reading in December in Mount Joy?
Average temperature in December
Mount Joy, PA
- Average high temperature in December: 41.2°F
The warmest month (with the highest average high temperature) is July (82.8°F).
The month with the lowest average high temperature is January (35.1°F).
- Average low temperature in December: 30°F
The month with the highest average low temperature is July (64°F).
The coldest month (with the lowest average low temperature) is January (22.5°F).
Average pressure in December
Mount Joy, PA
- Average pressure in December: 30.1"Hg
The month with the highest atmospheric pressure is November (30.13"Hg).
The month with the lowest atmospheric pressure is June (29.94"Hg).
Average wind speed in December
Mount Joy, PA
- Average wind speed in December: 8.1mph
The windiest month (with the highest average wind speed) is March (8.8mph).
The calmest month (with the lowest average wind speed) is August (4.9mph).
Average humidity in December
Mount Joy, PA
- Average humidity in December: 79%
The month with the highest relative humidity is May (81%).
The months with the lowest relative humidity are March and April (76%).
Average rainfall in December
Mount Joy, PA
- Average rainfall in December: 1.1"
The wettest month (with the highest rainfall) is August (1.97").
The driest month (with the least rainfall) is September (0.91").
Average rainfall days in December
Mount Joy, PA
- Average rainfall days in December: 8.6 days
The month with the highest number of rainy days is May (15.7 days).
The months with the least rainy days are January and November (6.6 days).
Average snowfall in December
Mount Joy, PA
- Average snowfall in December: 0.94"
The month with the highest snowfall is January (2.13").
The months with the least snowfall are May, June, July, August and September (0").
Average snowfall days in December
Mount Joy, PA
- Average snowfall days in December: 3.4 days
The month with the highest number of snowfall days is January (5.7 days).
The months with the least snowfall days are June, July, August and September (0 days).
Average daylight in December /
Average sunshine in December
Mount Joy, PA
- 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 24min).
- Average sunshine in December: 4h and 5min
The month with the most sunshine is July (Average sunshine: 10h and 36min).
The month with the least sunshine is February (Average sunshine: 4h and 30min).
Average sunshine days in December
Mount Joy, PA
- Average sunshine days in December: 19.2 days
The month with the most sunshine days is November (21.4 days).
The month with the least sunshine days is July (11.8 days).
Average UV index in December
Mount Joy, PA
- 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, PA
- 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 31).
Average visibility in December
Mount Joy, PA
- Average visibility in December: 6mi
The months with the highest visibility are January, February, March, April, June, July, August, October, November and December (6mi).
The months with the lowest visibility are May and September (5mi).
Mount Joy, Pennsylvania, USA
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