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 sea temperature 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
Portsmouth's December weather shows a modest shift in high-temperatures, falling from November's refreshing 58.3°F (14.6°C) to a fresh 51.4°F (10.8°C). Portsmouth, during the month of December, experiences an average low-temperature of 40.5°F (4.7°C).Humidity
The average relative humidity in December is 77%.Rainfall
In Portsmouth, in December, it is raining for 10.8 days, with typically 1.46" (37mm) of accumulated precipitation. In Portsmouth, during the entire year, the rain falls for 151.9 days and collects up to 20.35" (517mm) of precipitation.Snowfall
Months with snowfall in Portsmouth are January through March, November and December. In Portsmouth, in December, during 0.9 snowfall days, 0.24" (6mm) of snow is typically accumulated. Throughout the year, in Portsmouth, there are 5.3 snowfall days, and 1.18" (30mm) of snow is accumulated.Ocean temperature
In December, the average ocean temperature is 52.7°F (11.5°C).Note: With the appropriate swimsuit, one can swim in 52.7°F (11.5°C) even if temperatures dip below 50°F (10°C); otherwise, be ready for cold shock and breath issues. A fleeting swim around 55.4°F (13°C) is distressing.
Daylight
With an average of 9h and 42min of daylight, December has the shortest days of the year.On the first day of the month, sunrise is at 6:59 am and sunset at 4:49 pm. On the last day of December, sunrise is at 7:17 am and sunset at 4:59 pm EST.
Sunshine
In Portsmouth, the average sunshine in December is 5.5h.UV index
In December, the average daily maximum UV index in Portsmouth is 3. A UV Index of 3 to 5 symbolizes a medium health hazard from exposure to the Sun's UV radiation for ordinary individuals.Note: In December, the UV index of 3 transforms into the following advice:
Exercise prevention - Warding off sunburn is urged. When the Sun is at its strongest around midday, find shade and limit exposure. Sun protection is enhanced with clothing that boasts a tight weave yet offers a loose fit. Be advised! The UV radiation from the Sun can be almost doubled due to the reflective properties of snow.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
What is the usual temperature for Portsmouth in December?
What is the average humidity in December?
How much does it rain in December?
How many days does it snow in December?
How cold is the water in December?
What is the month with the shortest days?
How many hours of daylight does Portsmouth have in December?
When is the sunrise / sunset in December?
How long on average sun shines in December?
What is the UV index reading in December?
Average temperature in December
Portsmouth, VA
- Average high temperature in December: 51.4°F
The warmest month (with the highest average high temperature) is July (86.4°F).
The month with the lowest average high temperature is January (45.9°F).
- Average low temperature in December: 40.5°F
The month with the highest average low temperature is July (73.6°F).
The coldest month (with the lowest average low temperature) is January (34.7°F).
Average pressure in December
Portsmouth, VA
- Average pressure in December: 30.12"Hg
The month with the highest atmospheric pressure is November (30.13"Hg).
The month with the lowest atmospheric pressure is June (29.96"Hg).
Average wind speed in December
Portsmouth, VA
- Average wind speed in December: 9.1mph
The windiest months (with the highest average wind speed) are March and April (10.5mph).
The calmest month (with the lowest average wind speed) is August (7.5mph).
Average humidity in December
Portsmouth, VA
- Average humidity in December: 77%
The month with the highest relative humidity is May (78%).
The months with the lowest relative humidity are July and November (74%).
Average rainfall in December
Portsmouth, VA
- Average rainfall in December: 1.46"
The wettest month (with the highest rainfall) is August (2.52").
The driest month (with the least rainfall) is November (1.1").
Average rainfall days in December
Portsmouth, VA
- Average rainfall days in December: 10.8 days
The month with the highest number of rainy days is July (17.4 days).
The month with the least rainy days is November (8.3 days).
Average snowfall in December
Portsmouth, VA
- Average snowfall in December: 0.24"
The month with the highest snowfall is January (0.47").
The months with the least snowfall are April, May, June, July, August, September and October (0").
Average snowfall days in December
Portsmouth, VA
- Average snowfall days in December: 0.9 days
The month with the highest number of snowfall days is January (2.2 days).
The months with the least snowfall days are April, May, June, July, August, September and October (0 days).
Average sea temperature in December
Portsmouth, VA
- Average sea temperature in December: 52.7°F
The best month for swimming (with the highest average sea temperature) is August (80°F).
The coldest month (with the lowest average sea temperature) is February (44.5°F).
Average daylight in December /
Average sunshine in December
Portsmouth, VA
- Average daylight in December: 9h and 4min
The month with the longest days is June (Average daylight: 14h and 36min).
The month with the shortest days is December (Average daylight: 9h and 42min).
- Average sunshine in December: 5h and 3min
The month with the most sunshine is July (Average sunshine: 10h and 54min).
The month with the least sunshine is February (Average sunshine: 5h and 24min).
Average sunshine days in December
Portsmouth, VA
- Average sunshine days in December: 19.1 days
The month with the most sunshine days is October (19.5 days).
The month with the least sunshine days is August (10.8 days).
Average UV index in December
Portsmouth, VA
- Average UV index in December: 3
The months with the highest UV index are July and August (UV index 7).
The month with the lowest UV index is January (UV index 2).
Average cloud cover in December
Portsmouth, VA
- Average cloud cover in December: 41
The month with the most cloud cover is March (Cloud cover 44).
The month with the least cloud cover is July (Cloud cover 26).
Average visibility in December
Portsmouth, VA
- Average visibility in December: 6mi
The months with the highest visibility are January, February, March, April, May, June, July, August, September, October, November and December (6mi).
The months with the lowest visibility are January, February, March, April, May, June, July, August, September, October, November and December (6mi).
Portsmouth, Virginia, USA
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