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
The transition into December involves a small decrease in the average high-temperature, dipping slightly from a cool 52.2°F (11.2°C) in November to a frosty 43.5°F (6.4°C). In Glen Mills, the expected average low-temperature for December is an icy 32.5°F (0.3°C).Humidity
In December, the average relative humidity is 77%.Rainfall
In Glen Mills, in December, it is raining for 11.1 days, with typically 3.31" (84mm) of accumulated precipitation. Throughout the year, there are 166.6 rainfall days, and 35.59" (904mm) of precipitation is accumulated.Snowfall
Months with snowfall are January through May, October through December. In December, in Glen Mills, it is snowing for 3.4 days. Throughout December, 1.61" (41mm) of snow is accumulated. In Glen Mills, during the entire year, snow falls for 22 days and aggregates up to 11.81" (300mm) of snow.Daylight
The month with the shortest days is December, with an average of 9h and 24min of daylight.On the first day of December, sunrise is at 7:05 am and sunset at 4:37 pm. On the last day of the month, sunrise is at 7:23 am and sunset at 4:47 pm EST.
Sunshine
The average sunshine in December is 5h.UV index
The months with the lowest UV index are January, February, November and December, with an average maximum UV index of 2. A UV Index of 2, and less, symbolizes a minimal health vulnerability from exposure to the Sun's UV radiation for the ordinary person.Note: The UV index of 2 during December leads to these advisories:
Most people can stay in the Sun for up to 1 hour without burning, apart from children that always must be protected from sun exposure. Avoiding direct sun during mid-day hours can prevent harmful UV radiation exposure. Wearing sunglasses with both UVA and UVB protection effectively reduces sun-induced eye damage. Be attentive! The reflective property of snow can nearly double the Sun's UV radiation.
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 many days does it snow in December?
What is the month with the shortest days?
How many hours of daylight does Glen Mills have in December?
When are sunrise and sunset in December?
How many hours of sunshine does Glen Mills have in December?
What is the month with the lowest UV index?
What is the UV index intensity in December?
Average temperature in December
Glen Mills, PA
- Average high temperature in December: 43.5°F
The warmest month (with the highest average high temperature) is July (85.6°F).
The month with the lowest average high temperature is January (37°F).
- Average low temperature in December: 32.5°F
The month with the highest average low temperature is July (68.5°F).
The coldest month (with the lowest average low temperature) is January (25.3°F).
Average pressure in December
Glen Mills, 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
Glen Mills, PA
- Average wind speed in December: 8mph
The windiest months (with the highest average wind speed) are January and March (8.5mph).
The calmest month (with the lowest average wind speed) is August (5.4mph).
Average humidity in December
Glen Mills, PA
- Average humidity in December: 77%
The months with the highest relative humidity are February and October (78%).
The month with the lowest relative humidity is April (72%).
Average rainfall in December
Glen Mills, PA
- Average rainfall in December: 3.31"
The wettest month (with the highest rainfall) is August (4.09").
The driest month (with the least rainfall) is January (2.36").
Average rainfall days in December
Glen Mills, PA
- Average rainfall days in December: 11.1 days
The month with the highest number of rainy days is May (18.5 days).
The month with the least rainy days is January (8.6 days).
Average snowfall in December
Glen Mills, PA
- Average snowfall in December: 1.61"
The month with the highest snowfall is February (3.19").
The months with the least snowfall are June, July, August and September (0").
Average snowfall days in December
Glen Mills, PA
- Average snowfall days in December: 3.4 days
The month with the highest number of snowfall days is January (6.9 days).
The months with the least snowfall days are June, July, August and September (0 days).
Average daylight in December /
Average sunshine in December
Glen Mills, 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: 5h and 0min
The month with the most sunshine is July (Average sunshine: 10h and 30min).
The month with the least sunshine is February (Average sunshine: 4h and 48min).
Average sunshine days in December
Glen Mills, PA
- Average sunshine days in December: 16.5 days
The month with the most sunshine days is November (18.4 days).
The month with the least sunshine days is July (10 days).
Average UV index in December
Glen Mills, 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, November and December (UV index 2).
Average cloud cover in December
Glen Mills, PA
- Average cloud cover in December: 47
The months with the most cloud cover are February and March (Cloud cover 48).
The month with the least cloud cover is July (Cloud cover 32).
Average visibility in December
Glen Mills, 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).
Glen Mills, Pennsylvania, USA
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