December weather forecastGreat Valley, NY
December
Weather in December
December, the first month of the winter in Great Valley, is still a cold month, with an average temperature fluctuating between 24.3°F (-4.3°C) and 34.2°F (1.2°C).Temperature
As Great Valley, New York, enters December, the average high-temperature decreases from the a chilly 43.7°F (6.5°C) of November to a wintry 34.2°F (1.2°C). Great Valley's December nights cool down to an average low-temperature of 24.3°F (-4.3°C).Humidity
In December, the average relative humidity in Great Valley is 88%.Rainfall
In Great Valley, during December, the rain falls for 9.2 days and regularly aggregates up to 2.17" (55mm) of precipitation. Throughout the year, in Great Valley, there are 159.5 rainfall days, and 28.03" (712mm) of precipitation is accumulated.Snowfall
January through May, October through December are months with snowfall in Great Valley, New York. In Great Valley, New York, in December, snow falls for 15.5 days, with typically accumulated 7.36" (187mm) of snow. In Great Valley, during the entire year, snow falls for 75.5 days and aggregates up to 34.17" (868mm) of snow.Daylight
The month with the shortest days is December, with an average of 9h and 12min of daylight.On the first day of the month, sunrise is at 7:24 am and sunset at 4:43 pm. On the last day of December, sunrise is at 7:43 am and sunset at 4:52 pm EST.
Sunshine
In December, the average sunshine is 2.5h.UV index
January, February and December, with an average maximum UV index of 1, are months with the lowest UV index. A UV Index of 2, and less, symbolizes a low threat to health from unprotected exposure to Sun's UV rays for average individuals.Note: In December, a regular UV index of 1 translates into these guidelines:
Most individuals can handle sun exposure for up to an hour without burning, but children must always be shielded from sun exposure. The Sun's UV radiation is especially harmful around midday, so reduce exposure and stay safe. Clothes that are both tight-knit and comfortably loose are prime choices for sun protection. Observe! Snow reflection can nearly intensify the Sun's UV radiation twofold.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in December
Great Valley, NY
- Average high temperature in December: 34.2°F
The warmest month (with the highest average high temperature) is July (77.5°F).
The month with the lowest average high temperature is January (28°F).
- Average low temperature in December: 24.3°F
The month with the highest average low temperature is July (57°F).
The coldest month (with the lowest average low temperature) is January (16.2°F).
Average pressure in December
Great Valley, NY
- Average pressure in December: 30.08"Hg
The month with the highest atmospheric pressure is November (30.11"Hg).
The month with the lowest atmospheric pressure is June (29.93"Hg).
Average wind speed in December
Great Valley, NY
- Average wind speed in December: 9.2mph
The windiest month (with the highest average wind speed) is January (10mph).
The calmest month (with the lowest average wind speed) is August (5.9mph).
Average humidity in December
Great Valley, NY
- Average humidity in December: 88%
The months with the highest relative humidity are January and February (89%).
The month with the lowest relative humidity is May (79%).
Average rainfall in December
Great Valley, NY
- Average rainfall in December: 2.17"
The wettest month (with the highest rainfall) is April (3.27").
The driest month (with the least rainfall) is September (1.69").
Average rainfall days in December
Great Valley, NY
- Average rainfall days in December: 9.2 days
The month with the highest number of rainy days is May (18.1 days).
The month with the least rainy days is January (6.7 days).
Average snowfall in December
Great Valley, NY
- Average snowfall in December: 7.36"
The month with the highest snowfall is February (8.98").
The months with the least snowfall are June, July, August and September (0").
Average snowfall days in December
Great Valley, NY
- Average snowfall days in December: 15.5 days
The month with the highest number of snowfall days is January (18.3 days).
The months with the least snowfall days are June, July, August and September (0 days).
Average daylight in December /
Average sunshine in December
Great Valley, NY
- Average daylight in December: 9h and 12min
The month with the longest days is June (Average daylight: 15h and 12min).
The month with the shortest days is December (Average daylight: 9h and 12min).
- Average sunshine in December: 2h and 30min
The months with the most sunshine are July and August (Average sunshine: 9h and 42min).
The month with the least sunshine is January (Average sunshine: 2h and 18min).
Average sunshine days in December
Great Valley, NY
- Average sunshine days in December: 8.8 days
The month with the most sunshine days is September (13.3 days).
The month with the least sunshine days is January (8.3 days).
Average UV index in December
Great Valley, NY
- Average UV index in December: 1
The months with the highest UV index are June, July and August (UV index 5).
The months with the lowest UV index are January, February and December (UV index 1).
Average cloud cover in December
Great Valley, NY
- Average cloud cover in December: 77
The month with the most cloud cover is January (Cloud cover 79).
The months with the least cloud cover are July and August (Cloud cover 39).
Average visibility in December
Great Valley, NY
- Average visibility in December: 5mi
The months with the highest visibility are March, April, May, June, July, August, September, October, November and December (5mi).
The months with the lowest visibility are January and February (4mi).
