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
December witnesses a gentle descent in average high-temperature, descending from November's fresh 51.4°F (10.8°C) to a chilly 43.3°F (6.3°C). Nighttime temperatures in Old Westbury record an average of 35.8°F (2.1°C) throughout December.Humidity
In Old Westbury, the average relative humidity in December is 74%.Rainfall
In Old Westbury, in December, during 8.5 rainfall days, 0.83" (21mm) of precipitation is typically accumulated. In Old Westbury, during the entire year, the rain falls for 103.6 days and collects up to 7.83" (199mm) of precipitation.Snowfall
January through March and December are months with snowfall. December is the first month it typically snows. Throughout December, in the average 2.8 snowfall days, it receives 0.39" (10mm) of snow. Throughout the year, there are 14.8 snowfall days, and 1.34" (34mm) of snow is accumulated.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 6:59 am and sunset at 4:27 pm. On the last day of the month, sunrise is at 7:18 am and sunset at 4:36 pm EST.
Sunshine
In Old Westbury, 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 minimal health vulnerability from unsafe exposure to UV radiation for ordinary individuals.Note: An average maximum UV index of 2 in December leads to these recommendations:
People with sensitive skin, children, and babies should always be protected from prolonged sun exposure. The Sun's harshest UV rays are around midday; it's wise to seek shade and limit time outdoors. Combat UV radiation's detrimental effects with sun-safe clothing and UV-blocking eyewear. Heads up! The UV radiation from the Sun can almost be doubled by snow reflection.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Is December cold?
What is the average humidity in December?
How many days does it rain in December in Old Westbury?
When does it start to snow?
What is the month with the shortest days?
How many hours of daylight does Old Westbury have in December?
What time are sunrise and sunset in December?
How long on average sun shines in December in Old Westbury?
When is the lowest UV index?
How high is the UV index in December?
Average temperature in December
Old Westbury, NY
- Average high temperature in December: 43.3°F
The warmest month (with the highest average high temperature) is July (80.1°F).
The month with the lowest average high temperature is January (37.4°F).
- Average low temperature in December: 35.8°F
The months with the highest average low temperature are July and August (71.2°F).
The coldest month (with the lowest average low temperature) is January (28.8°F).
Average pressure in December
Old Westbury, NY
- Average pressure in December: 30.07"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
Old Westbury, NY
- Average wind speed in December: 12.1mph
The windiest month (with the highest average wind speed) is January (12.5mph).
The calmest month (with the lowest average wind speed) is July (8.1mph).
Average humidity in December
Old Westbury, NY
- Average humidity in December: 74%
The months with the highest relative humidity are May and June (76%).
The month with the lowest relative humidity is November (71%).
Average rainfall in December
Old Westbury, NY
- Average rainfall in December: 0.83"
The wettest month (with the highest rainfall) is July (0.87").
The driest month (with the least rainfall) is September (0.35").
Average rainfall days in December
Old Westbury, NY
- Average rainfall days in December: 8.5 days
The month with the highest number of rainy days is July (11.3 days).
The month with the least rainy days is January (5.4 days).
Average snowfall in December
Old Westbury, NY
- Average snowfall in December: 0.39"
The month with the highest snowfall is March (0.43").
The months with the least snowfall are April, May, June, July, August, September, October and November (0").
Average snowfall days in December
Old Westbury, NY
- Average snowfall days in December: 2.8 days
The month with the highest number of snowfall days is January (4.4 days).
The months with the least snowfall days are May, June, July, August and September (0 days).
Average daylight in December /
Average sunshine in December
Old Westbury, 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 48min).
The month with the least sunshine is February (Average sunshine: 4h and 42min).
Average sunshine days in December
Old Westbury, NY
- Average sunshine days in December: 19.5 days
The month with the most sunshine days is January (22.4 days).
The month with the least sunshine days is July (16.9 days).
Average UV index in December
Old Westbury, 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
Old Westbury, NY
- Average cloud cover in December: 48
The month with the most cloud cover is December (Cloud cover 48).
The months with the least cloud cover are July and August (Cloud cover 28).
Average visibility in December
Old Westbury, 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).
Old Westbury, New York, USA
Weather forecast for your location
2. Allow the app to use your location