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
In December, the average high-temperature marginally decreases from a cool 52.7°F (11.5°C) in November to a frosty 45°F (7.2°C). A mean low-temperature of 37.9°F (3.3°C) is a distinguishing feature of December, indicating a slight dip from daytime highs.Humidity
In December, the average relative humidity is 74%.Rainfall
The month with the most rainfall is December, when the rain falls for 12.8 days and typically aggregates up to 3.82" (97mm) of precipitation.Snowfall
Months with snowfall are January through March, November and December. In Shelter Island Heights, in December, during 2.3 snowfall days, 0.91" (23mm) of snow is typically accumulated. In Shelter Island Heights, during the entire year, snow falls for 13.9 days and aggregates up to 6.61" (168mm) of snow.Ocean temperature
In December, the average ocean temperature in Shelter Island Heights is 48.9°F (9.4°C).Note: Dipping into 48.9°F (9.4°C) below 50°F (10°C) needs protective wear, or you'd face cold shock and breathing issues swiftly. Meanwhile, a slight swim around 55.4°F (13°C) feels cold to the bone.
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 6:55 am and sunset at 4:21 pm. On the last day of the month, sunrise is at 7:14 am and sunset at 4:31 pm EST.
Sunshine
December has the least sunshine of the year, with an average of 4.6h of sunshine.UV index
January through March and December, with an average maximum UV index of 2, are months with the lowest UV index. A UV Index of 2, and less, symbolizes a minimal health hazard from unprotected exposure to Sun's UV rays for the ordinary person.Note: A maximum UV index of 2 in December translates 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. It's crucial to reduce time in the direct Sun around mid-day due to the intense solar radiation. Boost your sun resistance with garments that are densely woven yet spacious. Forewarned is forearmed! The Sun's UV radiation can be almost doubled in intensity by snow reflection.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
What is the average December temperature?
What is the average humidity in December?
What is the wettest month?
How much does it rain in December?
How much does it snow in December?
What is the water temperature in December in Shelter Island Heights?
What is the month with the shortest days in Shelter Island Heights?
How many hours of daylight does Shelter Island Heights have in December?
When is the sunrise / sunset in December?
What is the month with the least sunshine?
How long on average sun shines in December?
What is the month with the lowest UV index?
What is the UV index intensity in December?
Average temperature in December
Shelter Island Heights, NY
- Average high temperature in December: 45°F
The warmest month (with the highest average high temperature) is August (75.9°F).
The month with the lowest average high temperature is January (38.8°F).
- Average low temperature in December: 37.9°F
The month with the highest average low temperature is August (71.2°F).
The coldest month (with the lowest average low temperature) is January (31.3°F).
Average pressure in December
Shelter Island Heights, NY
- Average pressure in December: 30.05"Hg
The month with the highest atmospheric pressure is November (30.08"Hg).
The month with the lowest atmospheric pressure is June (29.93"Hg).
Average wind speed in December
Shelter Island Heights, NY
- Average wind speed in December: 15.7mph
The windiest month (with the highest average wind speed) is January (16mph).
The calmest month (with the lowest average wind speed) is July (10.4mph).
Average humidity in December
Shelter Island Heights, NY
- Average humidity in December: 74%
The months with the highest relative humidity are May and June (81%).
The month with the lowest relative humidity is November (72%).
Average rainfall in December
Shelter Island Heights, NY
- Average rainfall in December: 3.82"
The wettest month (with the highest rainfall) is December (3.82").
The driest month (with the least rainfall) is September (2.17").
Average rainfall days in December
Shelter Island Heights, NY
- Average rainfall days in December: 12.8 days
The month with the highest number of rainy days is May (15.3 days).
The month with the least rainy days is January (9.1 days).
Average snowfall in December
Shelter Island Heights, NY
- Average snowfall in December: 0.91"
The month with the highest snowfall is March (2.36").
The months with the least snowfall are April, May, June, July, August, September and October (0").
Average snowfall days in December
Shelter Island Heights, NY
- Average snowfall days in December: 2.3 days
The month with the highest number of snowfall days is January (4.2 days).
The months with the least snowfall days are May, June, July, August, September and October (0 days).
Average sea temperature in December
Shelter Island Heights, NY
- Average sea temperature in December: 48.9°F
The best month for swimming (with the highest average sea temperature) is August (72.1°F).
The coldest month (with the lowest average sea temperature) is February (38.8°F).
Average daylight in December /
Average sunshine in December
Shelter Island Heights, 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 4min
The months with the most sunshine are July and August (Average sunshine: 10h and 36min).
The month with the least sunshine is December (Average sunshine: 4h and 36min).
Average sunshine days in December
Shelter Island Heights, NY
- Average sunshine days in December: 13.7 days
The month with the most sunshine days is November (16.8 days).
The month with the least sunshine days is February (12.8 days).
Average UV index in December
Shelter Island Heights, 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 and December (UV index 2).
Average cloud cover in December
Shelter Island Heights, NY
- Average cloud cover in December: 52
The month with the most cloud cover is December (Cloud cover 52).
The month with the least cloud cover is August (Cloud cover 27).
Average visibility in December
Shelter Island Heights, 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).
Shelter Island Heights, New York, USA
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