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
In December, the average high-temperature goes from a chilly 48.7°F (9.3°C) in November to an icy 39°F (3.9°C). December's average low-temperature reading in Sewickley settles at a freezing cold 28°F (-2.2°C).Humidity
In December, the average relative humidity is 84%.Rainfall
In Sewickley, in December, it is raining for 10.1 days, with typically 1.57" (40mm) of accumulated precipitation. In Sewickley, during the entire year, the rain falls for 154.8 days and collects up to 21.22" (539mm) of precipitation.Snowfall
January through May, October through December are months with snowfall. In Sewickley, Pennsylvania, in December, during 10.5 snowfall days, 1.69" (43mm) of snow is typically accumulated. Throughout the year, there are 49.9 snowfall days, and 10.12" (257mm) of snow is accumulated.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
The month with the lowest UV index in Sewickley is December, with an average maximum UV index of 1. A UV Index value of 2, and less, symbolizes a low health risk from exposure to the Sun's UV rays for average individuals.Note: In December, a daily maximum UV index of 1 leads to the following instructions:
While most can endure approximately an hour in the sun without burning, children always require protection from sunlight. The Sun's most intense and consequently most harmful UV radiation during midday hours should be decreased by minimizing exposure and seeking shade. In bright sunlight, prioritize sunglasses that grant protection from UVA and UVB radiation. Be aware! The reflective nature of snow can magnify the Sun's UV radiation almost twofold.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Is December cold?
What is the average humidity in December?
How much does it rain in December?
How much does it snow in December?
What is the month with the shortest days?
What is the average length of the day in December?
What time are sunrise and sunset in December?
How long on average sun shines in December?
What is the month with the lowest UV index?
What is the UV index reading in December?
Average temperature in December
Sewickley, 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
Sewickley, 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
Sewickley, 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
Sewickley, 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
Sewickley, 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
Sewickley, 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
Sewickley, 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
Sewickley, 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
Sewickley, 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 18min).
- Average sunshine in December: 3h and 1min
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
Sewickley, 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
Sewickley, 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
Sewickley, 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
Sewickley, 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).
Sewickley, Pennsylvania, USA
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