December weather forecastMonongahela, PA
December
Weather in December
December, the first month of the winter in Monongahela, is also a wintry month, with temperature in the range of an average low of 28.8°F (-1.8°C) and an average high of 40.1°F (4.5°C).Temperature
The start of December involves a temperature drop, moving from a chilly 49.8°F (9.9°C) in November to a wintry 40.1°F (4.5°C). Throughout December, the temperature falls to an average low of 28.8°F (-1.8°C).Humidity
In Monongahela, the average relative humidity in December is 83%.Rainfall
In December, the rain falls for 11.3 days. Throughout December, 1.5" (38mm) of precipitation is accumulated. Throughout the year, there are 161.6 rainfall days, and 20" (508mm) of precipitation is accumulated.Snowfall
Months with snowfall are January through April, October through December. In Monongahela, in December, snow falls for 10.9 days, with typically accumulated 1.89" (48mm) of snow. In Monongahela, during the entire year, snow falls for 49.7 days and aggregates up to 9.76" (248mm) of snow.Daylight
December has the shortest days of the year, with an average of 9h and 24min of daylight.On the first day of December in Monongahela, sunrise is at 7:23 am and sunset at 4:54 pm. On the last day of the month, sunrise is at 7:42 am and sunset at 5:04 pm EST.
Sunshine
The average sunshine in December is 3.5h.UV index
December is the month with the lowest UV index, with an average maximum UV index of 1. A UV Index of 2, and less, symbolizes a low threat to health from exposure to the Sun's UV radiation for the average person.Note: The maximum daily UV index of 1 in December interprets into the following recommendations:
Though the majority can handle prolonged sun exposure, it is crucial to always shield babies, children, and those with fair skin. The most potent solar radiation is around mid-day, so one should minimize exposure to direct sunlight during this period. On bright days sunglasses that block both UVA and UVB rays should be worn. A hat with a wide brim is extremely helpful, as it can prevent roughly 50% of UV radiation from reaching the eyes. Be aware! The intensity of the Sun's UV radiation can be amplified nearly twice due to snow reflection.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in December
Monongahela, PA
- Average high temperature in December: 40.1°F
The warmest month (with the highest average high temperature) is July (83.7°F).
The month with the lowest average high temperature is January (34°F).
- Average low temperature in December: 28.8°F
The month with the highest average low temperature is July (62.2°F).
The coldest month (with the lowest average low temperature) is January (21.2°F).
Average pressure in December
Monongahela, PA
- Average pressure in December: 30.11"Hg
The month with the highest atmospheric pressure is November (30.14"Hg).
The month with the lowest atmospheric pressure is June (29.95"Hg).
Average wind speed in December
Monongahela, PA
- Average wind speed in December: 7.1mph
The windiest month (with the highest average wind speed) is January (7.8mph).
The calmest month (with the lowest average wind speed) is August (4.6mph).
Average humidity in December
Monongahela, PA
- Average humidity in December: 83%
The months with the highest relative humidity are January and February (84%).
The months with the lowest relative humidity are April, July and August (76%).
Average rainfall in December
Monongahela, PA
- Average rainfall in December: 1.5"
The wettest month (with the highest rainfall) is May (2.32").
The driest month (with the least rainfall) is January (1.18").
Average rainfall days in December
Monongahela, PA
- Average rainfall days in December: 11.3 days
The month with the highest number of rainy days is May (18.6 days).
The month with the least rainy days is January (9 days).
Average snowfall in December
Monongahela, PA
- Average snowfall in December: 1.89"
The month with the highest snowfall is January (2.44").
The months with the least snowfall are May, June, July, August and September (0").
Average snowfall days in December
Monongahela, PA
- Average snowfall days in December: 10.9 days
The month with the highest number of snowfall days is January (14 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
Monongahela, PA
- Average daylight in December: 9h and 24min
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: 3h and 30min
The month with the most sunshine is August (Average sunshine: 10h and 18min).
The month with the least sunshine is January (Average sunshine: 3h and 0min).
Average sunshine days in December
Monongahela, PA
- Average sunshine days in December: 12.4 days
The month with the most sunshine days is November (17.6 days).
The month with the least sunshine days is February (9 days).
Average UV index in December
Monongahela, PA
- Average UV index in December: 1
The months with the highest UV index are May, June, July and August (UV index 6).
The month with the lowest UV index is December (UV index 1).
Average cloud cover in December
Monongahela, PA
- Average cloud cover in December: 64
The month with the most cloud cover is January (Cloud cover 68).
The month with the least cloud cover is August (Cloud cover 33).
Average visibility in December
Monongahela, 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).





