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
During Rock Glen's transition into December, the average high-temperature lessens, moving from a frosty 46.9°F (8.3°C) in November to a cold 37.2°F (2.9°C). Rock Glen's nighttime temperature in December falls to an average of 26.2°F (-3.2°C).Humidity
The average relative humidity in December is 83%.Rainfall
In Rock Glen, in December, it is raining for 7.3 days, with typically 0.87" (22mm) of accumulated precipitation. In Rock Glen, during the entire year, the rain falls for 111.5 days and collects up to 11.34" (288mm) of precipitation.Snowfall
Months with snowfall are January through May, October through December. In Rock Glen, in December, during 5.3 snowfall days, 1.02" (26mm) of snow is typically accumulated. Throughout the year, there are 31.5 snowfall days, and 7.28" (185mm) 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 7:10 am and sunset at 4:37 pm. On the last day of the month, sunrise is at 7:29 am and sunset at 4:46 pm EST.
Sunshine
The average sunshine in December is 3.9h.UV index
January through March, October through December, with an average maximum UV index of 2, are months with the lowest UV index. A UV Index reading of 2, and below, represents a minimal health hazard from exposure to the Sun's UV radiation for the ordinary person.Note: The daily high UV index of 2 in December translates into this advice:
While most individuals can withstand prolonged sun exposure, it is imperative that babies, children, and those with sensitive skin always be shielded. The midday Sun can be harmful due to its potent UV radiation; seek shade and reduce exposure. Select sunglasses that boast both UVA and UVB protection to limit the adverse effects of the sun on the eyes. Remember! The Sun's UV radiation can be magnified almost twofold by the reflection of snow.
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?
How many days does it snow in December?
What is the month with the shortest days?
What is the average length of the day in December in Rock Glen?
What time are sunrise and sunset in December?
How many hours of sunshine does Rock Glen have in December?
What is the month with the lowest UV index?
What is the UV index reading in December in Rock Glen?
Average temperature in December
Rock Glen, PA
- Average high temperature in December: 37.2°F
The warmest month (with the highest average high temperature) is July (81°F).
The month with the lowest average high temperature is January (31.5°F).
- Average low temperature in December: 26.2°F
The month with the highest average low temperature is July (59.5°F).
The coldest month (with the lowest average low temperature) is January (18.9°F).
Average pressure in December
Rock Glen, PA
- Average pressure in December: 30.09"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
Rock Glen, PA
- Average wind speed in December: 7.8mph
The windiest month (with the highest average wind speed) is March (8.5mph).
The calmest month (with the lowest average wind speed) is August (5.1mph).
Average humidity in December
Rock Glen, PA
- Average humidity in December: 83%
The month with the highest relative humidity is February (84%).
The month with the lowest relative humidity is April (78%).
Average rainfall in December
Rock Glen, PA
- Average rainfall in December: 0.87"
The wettest month (with the highest rainfall) is May (1.26").
The driest month (with the least rainfall) is September (0.55").
Average rainfall days in December
Rock Glen, PA
- Average rainfall days in December: 7.3 days
The month with the highest number of rainy days is May (13.8 days).
The month with the least rainy days is January (5.4 days).
Average snowfall in December
Rock Glen, PA
- Average snowfall in December: 1.02"
The month with the highest snowfall is February (1.81").
The months with the least snowfall are June, July, August and September (0").
Average snowfall days in December
Rock Glen, PA
- Average snowfall days in December: 5.3 days
The month with the highest number of snowfall days is January (9.9 days).
The months with the least snowfall days are June, July, August and September (0 days).
Average daylight in December /
Average sunshine in December
Rock Glen, PA
- 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: 3h and 5min
The month with the most sunshine is July (Average sunshine: 9h and 54min).
The month with the least sunshine is February (Average sunshine: 3h and 36min).
Average sunshine days in December
Rock Glen, PA
- Average sunshine days in December: 19 days
The month with the most sunshine days is November (20.6 days).
The month with the least sunshine days is May (14.3 days).
Average UV index in December
Rock Glen, PA
- Average UV index in December: 2
The month with the highest UV index is July (UV index 6).
The months with the lowest UV index are January, February, March, October, November and December (UV index 2).
Average cloud cover in December
Rock Glen, PA
- Average cloud cover in December: 60
The month with the most cloud cover is February (Cloud cover 61).
The month with the least cloud cover is July (Cloud cover 37).
Average visibility in December
Rock Glen, PA
- Average visibility in December: 5mi
The month with the highest visibility is April (6mi).
The months with the lowest visibility are January, February, March, May, June, July, August, September, October, November and December (5mi).
Rock Glen, Pennsylvania, USA
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