December weather forecastYaphank, NY
December
Weather in December
December, the first month of the winter in Yaphank, is still a chilly month, with temperature in the range of an average high of 44.8°F (7.1°C) and an average low of 37°F (2.8°C).Temperature
A modest decline in the average high-temperature is seen during December, decreasing from a cool 52.5°F (11.4°C) in November to a chilly 44.8°F (7.1°C). During the December nights, Yaphank's temperature maintains an average close to the daytime highs, settling at an icy 37°F (2.8°C).Humidity
In December, the average relative humidity is 74%.Rainfall
December is the month with the most rainfall. Rain falls for 12.8 days and accumulates 3.31" (84mm) of precipitation.Snowfall
January through April, November and December are months with snowfall in Yaphank. In Yaphank, in December, during 3.4 snowfall days, 0.63" (16mm) of snow is typically accumulated. In Yaphank, during the entire year, snow falls for 17.9 days and aggregates up to 4.57" (116mm) of snow.Daylight
With an average of 9h and 18min of daylight, December has the shortest days of the year.On the first day of the month, sunrise is at 6:57 am and sunset at 4:24 pm. On the last day of December, sunrise is at 7:15 am and sunset at 4:34 pm EST.
Sunshine
In Yaphank, the average sunshine in December is 4.9h.UV index
The months with the lowest UV index are January through March and December, with an average maximum UV index of 2. A UV Index estimate of 2, and below, represents a low threat to health from unsafe exposure to UV radiation for the average person.Note: In December, the maximum UV index of 2 suggests this advice:
Despite the majority tolerating prolonged sun exposure, those with sensitive skin, infants, and children demand continual protection. Being exposed to the midday Sun can have harmful effects due to strong UV radiation; always take precautions. To mitigate harm from sun exposure, pick sunglasses offering UVA and UVB defense. Mind you! Snow reflection can increase the intensity of the Sun's UV radiation nearly twofold.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in December
Yaphank, NY
- Average high temperature in December: 44.8°F
The warmest month (with the highest average high temperature) is August (77.5°F).
The month with the lowest average high temperature is January (38.7°F).
- Average low temperature in December: 37°F
The months with the highest average low temperature are July and August (71.4°F).
The coldest month (with the lowest average low temperature) is January (30.6°F).
Average pressure in December
Yaphank, NY
- Average pressure in December: 30.06"Hg
The month with the highest atmospheric pressure is November (30.09"Hg).
The month with the lowest atmospheric pressure is June (29.93"Hg).
Average wind speed in December
Yaphank, NY
- Average wind speed in December: 14mph
The windiest month (with the highest average wind speed) is January (14.5mph).
The calmest months (with the lowest average wind speed) are July and August (9.6mph).
Average humidity in December
Yaphank, NY
- Average humidity in December: 74%
The month with the highest relative humidity is May (80%).
The month with the lowest relative humidity is November (71%).
Average rainfall in December
Yaphank, NY
- Average rainfall in December: 3.31"
The wettest month (with the highest rainfall) is December (3.31").
The driest months (with the least rainfall) are January, February and September (2.01").
Average rainfall days in December
Yaphank, NY
- Average rainfall days in December: 12.8 days
The month with the highest number of rainy days is July (16 days).
The month with the least rainy days is February (9 days).
Average snowfall in December
Yaphank, NY
- Average snowfall in December: 0.63"
The month with the highest snowfall is January (1.5").
The months with the least snowfall are May, June, July, August, September and October (0").
Average snowfall days in December
Yaphank, NY
- Average snowfall days in December: 3.4 days
The month with the highest number of snowfall days is February (5.4 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
Yaphank, NY
- Average daylight in December: 9h and 18min
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 54min
The months with the most sunshine are July and August (Average sunshine: 10h and 48min).
The month with the least sunshine is February (Average sunshine: 4h and 48min).
Average sunshine days in December
Yaphank, NY
- Average sunshine days in December: 13.5 days
The month with the most sunshine days is November (17.2 days).
The month with the least sunshine days is February (12.8 days).
Average UV index in December
Yaphank, 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
Yaphank, NY
- Average cloud cover in December: 49
The month with the most cloud cover is December (Cloud cover 49).
The month with the least cloud cover is August (Cloud cover 26).
Average visibility in December
Yaphank, 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).





