December weather forecastWater Mill, NY
December
Weather in December
December, the first month of the winter in Water Mill, is also a frosty month, with an average temperature ranging between min 38.3°F (3.5°C) and max 45.3°F (7.4°C).Temperature
The transition into December subtly indicates a reduction in the average high-temperature, down to a chilly 45.3°F (7.4°C) from November's cool 52.9°F (11.6°C). Water Mill maintains an average low-temperature of 38.3°F (3.5°C) throughout December's nights.Humidity
In December, the average relative humidity is 74%.Rainfall
The wettest months are October and December, with an average 2.6" (66mm) of rainfall.Snowfall
January through March, May, November and December are months with snowfall. In Water Mill, during December, snow falls for 2.5 days and regularly aggregates up to 0.75" (19mm) of snow. In Water Mill, during the entire year, snow falls for 15.6 days and aggregates up to 5.16" (131mm) of snow.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 4:22 pm. On the last day of the month, sunrise is at 7:13 am and sunset at 4:31 pm EST.
Sunshine
December has the least sunshine of the year, with an average of 4.7h of sunshine.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 minimal health hazard from exposure to the Sun's UV rays for the ordinary person.Note: The maximum UV index, 2 during December, leads to the following recommendations:
Long-term sun exposure is typically not a concern for most. However, those with sensitive skin, infants, and children must always have protection. Direct exposure to the Sun during its peak hours around mid-day should be minimized for safety. Sun-related eye harm can be minimized with proper sunglasses offering UVA and UVB coverage. Foresee this! The reflection from snow can nearly double the intensity of UV radiation from the Sun.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in December
Water Mill, NY
- Average high temperature in December: 45.3°F
The warmest month (with the highest average high temperature) is August (75.7°F).
The month with the lowest average high temperature is January (39°F).
- Average low temperature in December: 38.3°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 (31.5°F).
Average pressure in December
Water Mill, 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
Water Mill, NY
- Average wind speed in December: 15.9mph
The windiest month (with the highest average wind speed) is January (16.3mph).
The calmest month (with the lowest average wind speed) is July (10.7mph).
Average humidity in December
Water Mill, NY
- Average humidity in December: 74%
The month with the highest relative humidity is May (82%).
The month with the lowest relative humidity is November (72%).
Average rainfall in December
Water Mill, NY
- Average rainfall in December: 2.6"
The wettest months (with the highest rainfall) are October and December (2.6").
The driest month (with the least rainfall) is September (1.5").
Average rainfall days in December
Water Mill, NY
- Average rainfall days in December: 11.8 days
The months with the highest number of rainy days are May and July (14.8 days).
The months with the least rainy days are January and February (8.8 days).
Average snowfall in December
Water Mill, NY
- Average snowfall in December: 0.75"
The month with the highest snowfall is March (1.57").
The months with the least snowfall are April, June, July, August, September and October (0").
Average snowfall days in December
Water Mill, NY
- Average snowfall days in December: 2.5 days
The month with the highest number of snowfall days is February (4.8 days).
The months with the least snowfall days are June, July, August, September and October (0 days).
Average daylight in December /
Average sunshine in December
Water Mill, 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 42min
The month with the most sunshine is August (Average sunshine: 10h and 42min).
The month with the least sunshine is December (Average sunshine: 4h and 42min).
Average sunshine days in December
Water Mill, NY
- Average sunshine days in December: 14.5 days
The month with the most sunshine days is November (17.5 days).
The month with the least sunshine days is July (13.9 days).
Average UV index in December
Water Mill, 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
Water Mill, NY
- Average cloud cover in December: 51
The month with the most cloud cover is December (Cloud cover 51).
The month with the least cloud cover is August (Cloud cover 26).
Average visibility in December
Water Mill, 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).





