December weather forecastGlenwillard, PA
December
Weather in December
December, the first month of the winter in Glenwillard, is also a wintry month, with an average temperature fluctuating between 28°F (-2.2°C) and 39°F (3.9°C).Temperature
December brings a decrease in the average high-temperature, falling from November's frosty 48.7°F (9.3°C) to a cold 39°F (3.9°C). An average nighttime temperature of 28°F (-2.2°C) is noted during the month of December.Humidity
The average relative humidity in December is 84%.Rainfall
In Glenwillard, in December, it is raining for 10.1 days, with typically 1.57" (40mm) of accumulated precipitation. Throughout the year, there are 154.8 rainfall days, and 21.22" (539mm) of precipitation is accumulated.Snowfall
Months with snowfall are January through May, October through December. In December, it is snowing for 10.5 days. Throughout December, 1.69" (43mm) of snow is accumulated. In Glenwillard, during the entire year, snow falls for 49.9 days and aggregates up to 10.12" (257mm) of snow.Daylight
December has the shortest days of the year, with an average of 9h and 18min of daylight.On the first day of December, sunrise is at 7:25 am and sunset at 4:54 pm. On the last day of the month, sunrise is at 7:44 am and sunset at 5:04 pm EST.
Sunshine
In December, the average sunshine is 3.2h.UV index
With an average maximum UV index of 1, December is the month with the lowest UV index. A UV Index of 2, and less, symbolizes a low health risk from unsafe exposure to UV radiation for average individuals.Note: The daily maximum UV index of 1 in December interprets into the following advice:
Children, babies, and those with sensitive skin should always be shielded from long periods of sun exposure. The most potent solar radiation is around mid-day, so one should minimize exposure to direct sunlight during this period. To mitigate harm from sun exposure, pick sunglasses offering UVA and UVB defense. Be mindful! The reflection from snow can increase the Sun's UV radiation nearly twice.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in December
Glenwillard, PA
- Average high temperature in December: 39°F
The warmest month (with the highest average high temperature) is July (83.5°F).
The month with the lowest average high temperature is January (32.9°F).
- Average low temperature in December: 28°F
The month with the highest average low temperature is July (61.9°F).
The coldest month (with the lowest average low temperature) is January (20.3°F).
Average pressure in December
Glenwillard, PA
- Average pressure in December: 30.11"Hg
The month with the highest atmospheric pressure is November (30.13"Hg).
The month with the lowest atmospheric pressure is June (29.95"Hg).
Average wind speed in December
Glenwillard, PA
- Average wind speed in December: 7.4mph
The windiest month (with the highest average wind speed) is January (8.1mph).
The calmest month (with the lowest average wind speed) is August (4.7mph).
Average humidity in December
Glenwillard, PA
- Average humidity in December: 84%
The month with the highest relative humidity is February (85%).
The months with the lowest relative humidity are July and August (75%).
Average rainfall in December
Glenwillard, PA
- Average rainfall in December: 1.57"
The wettest month (with the highest rainfall) is July (2.36").
The driest month (with the least rainfall) is January (1.22").
Average rainfall days in December
Glenwillard, PA
- Average rainfall days in December: 10.1 days
The month with the highest number of rainy days is May (17.5 days).
The month with the least rainy days is January (8.1 days).
Average snowfall in December
Glenwillard, PA
- Average snowfall in December: 1.69"
The month with the highest snowfall is February (2.76").
The months with the least snowfall are June, July, August and September (0").
Average snowfall days in December
Glenwillard, PA
- Average snowfall days in December: 10.5 days
The month with the highest number of snowfall days is January (14.3 days).
The months with the least snowfall days are June, July, August and September (0 days).
Average daylight in December /
Average sunshine in December
Glenwillard, PA
- Average daylight in December: 9h and 18min
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 18min).
- Average sunshine in December: 3h and 12min
The month with the most sunshine is August (Average sunshine: 10h and 0min).
The month with the least sunshine is January (Average sunshine: 2h and 54min).
Average sunshine days in December
Glenwillard, PA
- Average sunshine days in December: 12.9 days
The month with the most sunshine days is November (16.6 days).
The month with the least sunshine days is February (10.7 days).
Average UV index in December
Glenwillard, PA
- Average UV index in December: 1
The months with the highest UV index are May, June and July (UV index 6).
The month with the lowest UV index is December (UV index 1).
Average cloud cover in December
Glenwillard, PA
- Average cloud cover in December: 66
The month with the most cloud cover is January (Cloud cover 70).
The month with the least cloud cover is August (Cloud cover 34).
Average visibility in December
Glenwillard, PA
- Average visibility in December: 5mi
The months with the highest visibility are April, June, August and November (6mi).
The months with the lowest visibility are January, February, March, May, July, September, October and December (5mi).





