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
Start of December brings a shift in the average high-temperature, falling from November's fresh 50.9°F (10.5°C) to a wintry 41.9°F (5.5°C). In Mortonville, an average nighttime temperature of 30.6°F (-0.8°C) is expected during December.Humidity
In Mortonville, the average relative humidity in December is 80%.Rainfall
In Mortonville, in December, during 8.7 rainfall days, 1.54" (39mm) of precipitation is typically accumulated. Throughout the year, in Mortonville, there are 138.3 rainfall days, and 19.76" (502mm) of precipitation is accumulated.Snowfall
January through May, October through December are months with snowfall. In December, it is snowing for 2.7 days. Throughout December, 1.14" (29mm) of snow is accumulated. In Mortonville, during the entire year, snow falls for 19.6 days and aggregates up to 7.64" (194mm) 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 the month, sunrise is at 7:06 am and sunset at 4:38 pm. On the last day of December, sunrise is at 7:24 am and sunset at 4:48 pm EST.
Sunshine
In December, the average sunshine in Mortonville is 4.7h.UV index
January through March, November and December, with an average maximum UV index of 2, are months with the lowest UV index in Mortonville, Pennsylvania. A UV Index estimate of 2, and below, represents a low health risk from exposure to the Sun's UV radiation for ordinary individuals.Note: The maximum UV index of 2 during December translates into these guidelines:
Extended time in the sun generally does not harm most, but those with sensitive skin, infants, and children should always be protected. The Sun is at its harshest during midday; protect yourself by staying in shaded areas and minimizing exposure. In bright sunlight, prioritize sunglasses that grant protection from UVA and UVB radiation. Heads up! The UV radiation from the Sun can almost be doubled by snow reflection.
Frequently asked questions
Is December cold in Mortonville?
What is the average humidity in December in Mortonville?
How much does it rain in Mortonville in December?
How many days does it snow in December in Mortonville?
What is the month with the shortest days in Mortonville?
What is the average length of the day in December in Mortonville?
What time are sunrise and sunset in December in Mortonville?
How long on average sun shines in December in Mortonville?
When is the lowest UV index in Mortonville?
How high is the UV index in December in Mortonville?
Average temperature in December
Mortonville, PA
- Average high temperature in December: 41.9°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 (35.6°F).
- Average low temperature in December: 30.6°F
The month with the highest average low temperature is July (65.8°F).
The coldest month (with the lowest average low temperature) is January (23.4°F).
Average pressure in December
Mortonville, PA
- Average pressure in December: 30.1"Hg
The month with the highest atmospheric pressure is November (30.13"Hg).
The month with the lowest atmospheric pressure is June (29.94"Hg).
Average wind speed in December
Mortonville, PA
- Average wind speed in December: 8.3mph
The windiest months (with the highest average wind speed) are January, February and March (8.8mph).
The calmest month (with the lowest average wind speed) is August (5.2mph).
Average humidity in December
Mortonville, PA
- Average humidity in December: 80%
The months with the highest relative humidity are May and October (81%).
The month with the lowest relative humidity is April (76%).
Average rainfall in December
Mortonville, PA
- Average rainfall in December: 1.54"
The wettest month (with the highest rainfall) is August (2.72").
The driest month (with the least rainfall) is February (1.14").
Average rainfall days in December
Mortonville, PA
- Average rainfall days in December: 8.7 days
The month with the highest number of rainy days is July (16.8 days).
The month with the least rainy days is January (6.4 days).
Average snowfall in December
Mortonville, PA
- Average snowfall in December: 1.14"
The month with the highest snowfall is March (2.32").
The months with the least snowfall are June, July, August and September (0").
Average snowfall days in December
Mortonville, 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 June, July, August and September (0 days).
Average daylight in December /
Average sunshine in December
Mortonville, 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 4min
The month with the most sunshine is July (Average sunshine: 10h and 24min).
The month with the least sunshine is February (Average sunshine: 4h and 30min).
Average sunshine days in December
Mortonville, PA
- Average sunshine days in December: 19.3 days
The month with the most sunshine days is November (20 days).
The month with the least sunshine days is July (12.4 days).
Average UV index in December
Mortonville, 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
Mortonville, PA
- Average cloud cover in December: 49
The month with the most cloud cover is February (Cloud cover 50).
The month with the least cloud cover is July (Cloud cover 33).
Average visibility in December
Mortonville, 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).
Mortonville, Pennsylvania, USA
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