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
December implies a gentle temperature shift, with average high-temperatures reducing from November's chilly 48.4°F (9.1°C) to an icy 38.5°F (3.6°C). An average low-temperature of 27.3°F (-2.6°C) is observed during the December nights.Humidity
February and December, with an average relative humidity of 82%, are the most humid months.Rainfall
In Portland, in December, it is raining for 9.3 days, with typically 2.13" (54mm) of accumulated precipitation. Throughout the year, there are 135.7 rainfall days, and 23.74" (603mm) of precipitation is accumulated.Snowfall
January through May, October through December are months with snowfall. In Portland, Pennsylvania, in December, during 5.7 snowfall days, 3.35" (85mm) of snow is typically accumulated. Throughout the year, there are 33.7 snowfall days, and 16.65" (423mm) of snow is accumulated.Daylight
With an average of 9h and 18min of daylight, December has the shortest days of the year.On the first day of the month, sunrise is at 7:06 am and sunset at 4:33 pm. On the last day of December, sunrise is at 7:24 am and sunset at 4:42 pm EST.
Sunshine
The average sunshine in December is 4.5h.UV index
December is the month with the lowest UV index, with an average maximum UV index of 1. A UV Index reading of 2, and below, represents a low threat to health from unprotected exposure to Sun's UV rays for ordinary individuals.Note: The UV index of 1 during December leads to these advisories:
Unlike children, who always need sun protection, most individuals can remain in the sun for up to an hour without getting burnt. Limiting sun exposure during midday hours helps in reducing the harmful effects of UV radiation. Protect your eyes, ears, face, and neck from the Sun by wearing a wide-brimmed hat. Guard yourself! Snow reflection can almost double the UV radiation from the Sun.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
How cold is it in December?
What is the most humid month?
What is the average humidity in December?
How many days 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 many hours of sunshine does Portland have in December?
What is the month with the lowest UV index?
What is the UV index reading in December?
Average temperature in December
Portland, PA
- Average high temperature in December: 38.5°F
The warmest month (with the highest average high temperature) is July (82.4°F).
The month with the lowest average high temperature is January (32.9°F).
- Average low temperature in December: 27.3°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
Portland, PA
- Average pressure in December: 30.08"Hg
The month with the highest atmospheric pressure is November (30.11"Hg).
The month with the lowest atmospheric pressure is June (29.94"Hg).
Average wind speed in December
Portland, PA
- Average wind speed in December: 7.2mph
The windiest month (with the highest average wind speed) is March (7.9mph).
The calmest month (with the lowest average wind speed) is August (4.9mph).
Average humidity in December
Portland, PA
- Average humidity in December: 82%
The months with the highest relative humidity are February and December (82%).
The month with the lowest relative humidity is April (76%).
Average rainfall in December
Portland, PA
- Average rainfall in December: 2.13"
The wettest month (with the highest rainfall) is July (2.48").
The driest month (with the least rainfall) is September (1.22").
Average rainfall days in December
Portland, PA
- Average rainfall days in December: 9.3 days
The month with the highest number of rainy days is May (15.5 days).
The month with the least rainy days is January (5.8 days).
Average snowfall in December
Portland, PA
- Average snowfall in December: 3.35"
The month with the highest snowfall is March (3.82").
The months with the least snowfall are June, July, August and September (0").
Average snowfall days in December
Portland, PA
- Average snowfall days in December: 5.7 days
The month with the highest number of snowfall days is February (8.5 days).
The months with the least snowfall days are June, July, August and September (0 days).
Average daylight in December /
Average sunshine in December
Portland, PA
- Average daylight in December: 9h and 2min
The month with the longest days is June (Average daylight: 15h and 6min).
The month with the shortest days is December (Average daylight: 9h and 18min).
- Average sunshine in December: 4h and 3min
The month with the most sunshine is July (Average sunshine: 10h and 6min).
The month with the least sunshine is February (Average sunshine: 4h and 12min).
Average sunshine days in December
Portland, PA
- Average sunshine days in December: 17.7 days
The month with the most sunshine days is November (19.2 days).
The month with the least sunshine days is July (13.3 days).
Average UV index in December
Portland, PA
- Average UV index in December: 1
The month with the highest UV index is June (UV index 6).
The month with the lowest UV index is December (UV index 1).
Average cloud cover in December
Portland, PA
- Average cloud cover in December: 52
The month with the most cloud cover is February (Cloud cover 53).
The month with the least cloud cover is July (Cloud cover 37).
Average visibility in December
Portland, PA
- Average visibility in December: 5mi
The month with the highest visibility is April (6mi).
The months with the lowest visibility are January, February, March, May, June, July, August, September, October, November and December (5mi).
Portland, Pennsylvania, USA
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