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 the transition into December, Roslyn observes a decrease in the average high-temperature, falling from a cool 52.2°F (11.2°C) in November to a frosty 42.8°F (6°C). Roslyn's December nights cool down to an average low-temperature of 31.6°F (-0.2°C).Humidity
The months with the highest humidity are February, October and December, with an average relative humidity of 78%.Rainfall
In Roslyn, during December, the rain falls for 7.5 days and regularly aggregates up to 1.14" (29mm) of precipitation. In Roslyn, during the entire year, the rain falls for 122.4 days and collects up to 12.68" (322mm) of precipitation.Snowfall
Months with snowfall in Roslyn are January through April, November and December. In Roslyn, during December, snow falls for 2.5 days and regularly aggregates up to 0.71" (18mm) of snow. 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, sunrise is at 7:22 am and sunset at 4:45 pm EST.
Sunshine
In Roslyn, the average sunshine in December is 5h.UV index
The months with the lowest UV index in Roslyn, Pennsylvania, are January through March, November and December, with an average maximum UV index of 2. A UV Index value of 2, and less, symbolizes a minimal health vulnerability from exposure to the Sun's UV rays for ordinary individuals.Note: The maximum daily UV index of 2 in December interprets into the following recommendations:
Children must always have sun protection, unlike most people, who can tolerate up to an hour in the sun without any burns. The solar radiation is most powerful near the mid-day, so the exposure to the direct Sun should be reduced accordingly. On days when the sun blazes, arm yourself with sunglasses that block UVA and UVB radiation. Be attentive! The reflective property of snow can nearly double the Sun's UV radiation.
Frequently asked questions
Is December cold in Roslyn?
What are the most humid months in Roslyn?
What is the average humidity in December in Roslyn?
How many days does it rain in December in Roslyn?
How much does it snow in Roslyn in December?
What is the month with the shortest days in Roslyn?
How many hours of daylight does Roslyn have in December?
When are sunrise and sunset in December in Roslyn?
How long on average sun shines in December in Roslyn?
What are the months with the lowest UV index in Roslyn?
What is the UV index intensity in December in Roslyn?
Average temperature in December
Roslyn, 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
Roslyn, 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
Roslyn, 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
Roslyn, 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
Roslyn, 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
Roslyn, 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
Roslyn, 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
Roslyn, 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
Roslyn, 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
Roslyn, 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
Roslyn, 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
Roslyn, 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
Roslyn, 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).
Roslyn, Pennsylvania, USA
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