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 shift in Penllyn's weather is observed as November turns into December, with the average high temperature reducing from a cool 52.2°F (11.2°C) to a chilly 42.8°F (6°C). Throughout December, the average low-temperature dips to a freezing cold 31.6°F (-0.2°C).Humidity
February, October and December, with an average relative humidity of 78%, are the most humid months.Rainfall
In Penllyn, in December, it is raining for 7.5 days, with typically 1.14" (29mm) of accumulated precipitation. Throughout the year, there are 122.4 rainfall days, and 12.68" (322mm) of precipitation is accumulated.Snowfall
January through April, November and December are months with snowfall. In Penllyn, in December, during 2.5 snowfall days, 0.71" (18mm) of snow is typically accumulated. Throughout the year, there are 16.3 snowfall days, and 4.72" (120mm) of snow is accumulated.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 7:04 am and sunset at 4:35 pm. On the last day of December, in Penllyn, sunrise is at 7:23 am and sunset at 4:45 pm EST.
Sunshine
In December, the average sunshine is 5h.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 value of 2, and less, symbolizes a low health risk from unsafe exposure to UV radiation for average individuals.Note: A maximum high daily UV index of 2 during December translates into the following directions:
While most people are not greatly affected by extended sun exposure, those with fair skin, babies, and children must always have protection. Being exposed to the midday Sun can have harmful effects due to strong UV radiation; always take precautions. Shield yourself from the harmful effects of UV radiation with sun-protective attire, a hat, and quality sunglasses. Notice this! Nearly double the intensity of the Sun's UV radiation can be caused by snow reflection.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Is December cold?
What is the most humid month?
What is the average humidity in December?
How much does it rain in December?
How much does it snow in December?
What is the month with the shortest days?
How many hours of daylight does Penllyn have in December?
What time are sunrise and sunset in December?
How many hours of sunshine does Penllyn have in December?
What is the month with the lowest UV index?
What is the UV index intensity in December in Penllyn?
Average temperature in December
Penllyn, PA
- Average high temperature in December: 42.8°F
The warmest month (with the highest average high temperature) is July (86.2°F).
The month with the lowest average high temperature is January (36.7°F).
- Average low temperature in December: 31.6°F
The month with the highest average low temperature is July (68.2°F).
The coldest month (with the lowest average low temperature) is January (24.6°F).
Average pressure in December
Penllyn, PA
- 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
Penllyn, PA
- Average wind speed in December: 7.6mph
The windiest month (with the highest average wind speed) is March (8.4mph).
The calmest month (with the lowest average wind speed) is August (5.4mph).
Average humidity in December
Penllyn, PA
- Average humidity in December: 78%
The months with the highest relative humidity are February, October and December (78%).
The months with the lowest relative humidity are April, July and August (72%).
Average rainfall in December
Penllyn, PA
- Average rainfall in December: 1.14"
The wettest month (with the highest rainfall) is August (1.54").
The driest month (with the least rainfall) is September (0.75").
Average rainfall days in December
Penllyn, PA
- Average rainfall days in December: 7.5 days
The month with the highest number of rainy days is May (14.1 days).
The month with the least rainy days is November (6.4 days).
Average snowfall in December
Penllyn, PA
- Average snowfall in December: 0.71"
The month with the highest snowfall is February (1.46").
The months with the least snowfall are May, June, July, August, September and October (0").
Average snowfall days in December
Penllyn, PA
- Average snowfall days in December: 2.5 days
The month with the highest number of snowfall days is January (5.1 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
Penllyn, 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: 5h and 0min
The month with the most sunshine is July (Average sunshine: 10h and 42min).
The month with the least sunshine is February (Average sunshine: 4h and 48min).
Average sunshine days in December
Penllyn, PA
- Average sunshine days in December: 20.9 days
The month with the most sunshine days is November (21.3 days).
The month with the least sunshine days is May (14.4 days).
Average UV index in December
Penllyn, PA
- Average UV index in December: 2
The months with the highest UV index are May, 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 December
Penllyn, PA
- Average cloud cover in December: 47
The month with the most cloud cover is February (Cloud cover 48).
The month with the least cloud cover is July (Cloud cover 31).
Average visibility in December
Penllyn, 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).
Penllyn, Pennsylvania, USA
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