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's onset brings a reduction in the average high-temperature, from a cool 50.7°F (10.4°C) in November to an icy 41.5°F (5.3°C). In Graterford, December nights witness a steady temperature drop to a subzero cold 30.2°F (-1°C).Humidity
The average relative humidity in December is 79%.Rainfall
In Graterford, in December, it is raining for 9.5 days, with typically 2.32" (59mm) of accumulated precipitation. Throughout the year, there are 146.5 rainfall days, and 27.87" (708mm) of precipitation is accumulated.Snowfall
January through April, November and December are months with snowfall. In Graterford, in December, during 2.7 snowfall days, 1.89" (48mm) of snow is typically accumulated. Throughout the year, there are 19.1 snowfall days, and 11.54" (293mm) of snow is accumulated.Daylight
The month with the shortest days is December, with an average of 9h and 24min of daylight.On the first day of the month, sunrise is at 7:05 am and sunset at 4:36 pm. On the last day of December, sunrise is at 7:24 am and sunset at 4:46 pm EST.
Sunshine
In December, the average sunshine is 4.9h.UV index
January through March, November and December, with an average maximum UV index of 2, are months with the lowest UV index in Graterford. A UV Index value of 2, and less, symbolizes a low health risk from unprotected exposure to Sun's UV rays for average individuals.Note: The daily high UV index of 2 in December translates into this advice:
Extended time in the sun generally does not harm most, but those with sensitive skin, infants, and children should always be protected. For health reasons, it's advisable to reduce direct sun exposure during peak hours around midday. Wearing sunglasses with both UVA and UVB protection effectively reduces sun-induced eye damage. Alert! The snow's reflection can amplify the UV radiation of the Sun nearly twice.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
How cold is it in December?
What is the average humidity in December?
How many days does it rain in December?
How much does it snow in December?
What is the month with the shortest days?
What is the average length of the day in December?
When are sunrise and sunset in December?
How many hours of sunshine does Graterford have in December?
What are the months with the lowest UV index?
What is the UV index intensity in December?
Average temperature in December
Graterford, PA
- Average high temperature in December: 41.5°F
The warmest month (with the highest average high temperature) is July (84.2°F).
The month with the lowest average high temperature is January (35.4°F).
- Average low temperature in December: 30.2°F
The month with the highest average low temperature is July (65.5°F).
The coldest month (with the lowest average low temperature) is January (23.2°F).
Average pressure in December
Graterford, PA
- Average pressure in December: 30.1"Hg
The month with the highest atmospheric pressure is November (30.12"Hg).
The month with the lowest atmospheric pressure is June (29.94"Hg).
Average wind speed in December
Graterford, PA
- Average wind speed in December: 7.6mph
The windiest month (with the highest average wind speed) is March (8.1mph).
The calmest month (with the lowest average wind speed) is August (5mph).
Average humidity in December
Graterford, PA
- Average humidity in December: 79%
The months with the highest relative humidity are February and October (80%).
The months with the lowest relative humidity are April and July (75%).
Average rainfall in December
Graterford, PA
- Average rainfall in December: 2.32"
The wettest month (with the highest rainfall) is August (3.15").
The driest month (with the least rainfall) is September (1.81").
Average rainfall days in December
Graterford, PA
- Average rainfall days in December: 9.5 days
The months with the highest number of rainy days are May and July (17 days).
The month with the least rainy days is January (7.3 days).
Average snowfall in December
Graterford, PA
- Average snowfall in December: 1.89"
The month with the highest snowfall is March (3.7").
The months with the least snowfall are May, June, July, August, September and October (0").
Average snowfall days in December
Graterford, PA
- Average snowfall days in December: 2.7 days
The month with the highest number of snowfall days is January (5.8 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
Graterford, PA
- Average daylight in December: 9h and 2min
The month with the longest days is June (Average daylight: 15h and 0min).
The month with the shortest days is December (Average daylight: 9h and 24min).
- Average sunshine in December: 4h and 5min
The month with the most sunshine is July (Average sunshine: 10h and 36min).
The month with the least sunshine is February (Average sunshine: 4h and 42min).
Average sunshine days in December
Graterford, PA
- Average sunshine days in December: 19.4 days
The month with the most sunshine days is November (21 days).
The month with the least sunshine days is May (12.3 days).
Average UV index in December
Graterford, PA
- Average UV index in December: 2
The months with the highest UV index are May, June, July and August (UV index 6).
The months with the lowest UV index are January, February, March, November and December (UV index 2).
Average cloud cover in December
Graterford, PA
- Average cloud cover in December: 48
The month with the most cloud cover is February (Cloud cover 49).
The month with the least cloud cover is July (Cloud cover 32).
Average visibility in December
Graterford, PA
- Average visibility in December: 6mi
The months with the highest visibility are January, February, March, April, June, July, August, October, November and December (6mi).
The months with the lowest visibility are May and September (5mi).
Graterford, Pennsylvania, USA
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