December weather forecastMount Lebanon, PA
December
Weather in December
December, the first month of the winter in Mount Lebanon, is still a cold month, with an average temperature varying between 39.7°F (4.3°C) and 28.4°F (-2°C).Temperature
Mount Lebanon observes a minor decrease in the average high-temperature with the arrival of December, falling from November's chilly 49.3°F (9.6°C) to a wintry 39.7°F (4.3°C). December witnesses an average low-temperature hovering around a subzero cold 28.4°F (-2°C).Humidity
In December, the average relative humidity is 83%.Rainfall
In Mount Lebanon, in December, during 8.2 rainfall days, 0.87" (22mm) of precipitation is typically accumulated. In Mount Lebanon, during the entire year, the rain falls for 132.6 days and collects up to 11.5" (292mm) of precipitation.Snowfall
January through April, November and December are months with snowfall. In Mount Lebanon, in December, snow falls for 6.4 days, with typically accumulated 0.59" (15mm) of snow. Throughout the year, there are 32.5 snowfall days, and 3.66" (93mm) of snow is accumulated.Daylight
With an average of 9h and 24min of daylight, December has the shortest days of the year.On the first day of December, sunrise is at 7:24 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
In December, the average sunshine is 3.4h.UV index
With an average maximum UV index of 1, December is the month with the lowest UV index. A UV Index value of 2, and less, symbolizes a low health risk from exposure to the Sun's UV rays for ordinary individuals.Note: During December, 1 as the daily maximum UV index converts into the following advice:
Infants, children, and people with sensitive skin should always have protection against lengthy periods of sun exposure. Solar radiation peaks around mid-day, so it's wise to limit exposure to the Sun at this time. 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.
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Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in December
Mount Lebanon, PA
- Average high temperature in December: 39.7°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 (33.4°F).
- Average low temperature in December: 28.4°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°F).
Average pressure in December
Mount Lebanon, 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
Mount Lebanon, PA
- Average wind speed in December: 7.3mph
The windiest month (with the highest average wind speed) is January (7.9mph).
The calmest months (with the lowest average wind speed) are July and August (4.7mph).
Average humidity in December
Mount Lebanon, PA
- Average humidity in December: 83%
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
Mount Lebanon, PA
- Average rainfall in December: 0.87"
The wettest month (with the highest rainfall) is July (1.34").
The driest month (with the least rainfall) is November (0.67").
Average rainfall days in December
Mount Lebanon, PA
- Average rainfall days in December: 8.2 days
The month with the highest number of rainy days is July (15.6 days).
The month with the least rainy days is February (6.4 days).
Average snowfall in December
Mount Lebanon, PA
- Average snowfall in December: 0.59"
The month with the highest snowfall is February (0.98").
The months with the least snowfall are May, June, July, August, September and October (0").
Average snowfall days in December
Mount Lebanon, PA
- Average snowfall days in December: 6.4 days
The month with the highest number of snowfall days is January (9.3 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
Mount Lebanon, 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 24min
The month with the most sunshine is August (Average sunshine: 10h and 12min).
The month with the least sunshine is January (Average sunshine: 3h and 0min).
Average sunshine days in December
Mount Lebanon, PA
- Average sunshine days in December: 18.5 days
The month with the most sunshine days is November (19.6 days).
The month with the least sunshine days is May (12.2 days).
Average UV index in December
Mount Lebanon, PA
- Average UV index in December: 1
The months with the highest UV index are June, July and August (UV index 6).
The month with the lowest UV index is December (UV index 1).
Average cloud cover in December
Mount Lebanon, 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
Mount Lebanon, PA
- Average visibility in December: 5mi
The months with the highest visibility are April, June, July, August and November (6mi).
The months with the lowest visibility are January, February, March, May, September, October and December (5mi).





