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 sea temperature 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
Roslyn's December weather shows a modest shift in high-temperatures, falling from November's cool 51.1°F (10.6°C) to an icy 42.4°F (5.8°C). Roslyn's December nights witness minimal differential from the daytime temperatures, with averages of 34.7°F (1.5°C).Humidity
The months with the highest humidity are February, May and December, with an average relative humidity of 75%.Rainfall
December is the month with the most rainfall in Roslyn. Rain falls for 12.9 days and accumulates 4.06" (103mm) of precipitation.Snowfall
January through April, November and December are months with snowfall. In Roslyn, New York, in December, during 3.5 snowfall days, 1.54" (39mm) of snow is typically accumulated. In Roslyn, during the entire year, snow falls for 22.2 days and aggregates up to 7.24" (184mm) of snow.Ocean temperature
In Roslyn, New York, the average seawater temperature in December is 48°F (8.9°C).Note: If planning to swim in 48°F (8.9°C) under 50°F (10°C), wear a protective suit. Neglecting this advice might cause immediate cold shock and troubled breathing. A splash around 55.4°F (13°C) is not much warmer.
Daylight
December has the shortest days of the year, with an average of 9h and 18min of daylight.On the first day of the month, sunrise is at 7:00 am and sunset at 4:27 pm. On the last day of December, sunrise is at 7:18 am and sunset at 4:37 pm EST.
Sunshine
The average sunshine in December is 4.9h.UV index
January through March, November and December, with an average maximum UV index of 2, are months with the lowest UV index in Roslyn. A UV Index of 2, and less, symbolizes a low health risk from unprotected exposure to Sun's UV rays for ordinary individuals.Note: The UV index of 2 in December translates into these instructions:
Most individuals face no significant issues with extended sun exposure, but it is always essential to protect children, babies, and those with sensitive skin. Avoiding direct sun during mid-day hours can prevent harmful UV radiation exposure. Safeguard your eyes, ears, and face from sun rays with the aid of a wide-brim hat. Beware! Reflection from snow can magnify the Sun's UV radiation nearly twofold.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
How cold does it get in December?
What is the most humid month?
What is the average humidity in December?
What is the rainiest month?
How many days does it rain in December?
How much does it snow in December?
What is the water temperature in December?
What is the month with the shortest days?
How many hours of daylight does Roslyn have in December?
When are sunrise and sunset in December?
How many hours of sunshine does Roslyn have in December?
When is the lowest UV index?
How high is the UV index in December?
Average temperature in December
Roslyn, NY
- Average high temperature in December: 42.4°F
The warmest month (with the highest average high temperature) is July (81.5°F).
The month with the lowest average high temperature is January (36.5°F).
- Average low temperature in December: 34.7°F
The months with the highest average low temperature are July and August (70.3°F).
The coldest month (with the lowest average low temperature) is January (27.3°F).
Average pressure in December
Roslyn, NY
- Average pressure in December: 30.07"Hg
The month with the highest atmospheric pressure is November (30.1"Hg).
The month with the lowest atmospheric pressure is June (29.93"Hg).
Average wind speed in December
Roslyn, NY
- Average wind speed in December: 10.8mph
The windiest month (with the highest average wind speed) is January (11.2mph).
The calmest month (with the lowest average wind speed) is July (7.3mph).
Average humidity in December
Roslyn, NY
- Average humidity in December: 75%
The months with the highest relative humidity are February, May and December (75%).
The months with the lowest relative humidity are August and November (71%).
Average rainfall in December
Roslyn, NY
- Average rainfall in December: 4.06"
The wettest month (with the highest rainfall) is December (4.06").
The driest month (with the least rainfall) is September (2.4").
Average rainfall days in December
Roslyn, NY
- Average rainfall days in December: 12.9 days
The month with the highest number of rainy days is July (17.9 days).
The month with the least rainy days is January (9.3 days).
Average snowfall in December
Roslyn, NY
- Average snowfall in December: 1.54"
The month with the highest snowfall is March (2.01").
The months with the least snowfall are May, June, July, August, September and October (0").
Average snowfall days in December
Roslyn, NY
- Average snowfall days in December: 3.5 days
The month with the highest number of snowfall days is January (6.8 days).
The months with the least snowfall days are June, July, August, September and October (0 days).
Average sea temperature in December
Roslyn, NY
- Average sea temperature in December: 48.1°F
The best month for swimming (with the highest average sea temperature) is August (74.1°F).
The coldest month (with the lowest average sea temperature) is February (39.9°F).
Average daylight in December /
Average sunshine in December
Roslyn, NY
- 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: 4h and 5min
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, NY
- Average sunshine days in December: 15.5 days
The month with the most sunshine days is November (18 days).
The month with the least sunshine days is July (10.6 days).
Average UV index in December
Roslyn, NY
- Average UV index in December: 2
The months with the highest UV index are 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, NY
- Average cloud cover in December: 47
The months with the most cloud cover are February and December (Cloud cover 47).
The months with the least cloud cover are July and August (Cloud cover 29).
Average visibility in December
Roslyn, NY
- Average visibility in December: 6mi
The months with the highest visibility are January, February, March, April, May, June, July, August, September, October, November and December (6mi).
The months with the lowest visibility are January, February, March, April, May, June, July, August, September, October, November and December (6mi).
Roslyn, New York, USA
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