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
The start of December signals a gentle decrease in the average high-temperature, transitioning from a cool 51.1°F (10.6°C) in November to an icy 42.4°F (5.8°C). Portsmouth witnesses a consistent average low-temperature of 33.1°F (0.6°C) throughout December.Humidity
In Portsmouth, the average relative humidity in December is 75%.Rainfall
In Portsmouth, Rhode Island, in December, during 11.5 rainfall days, 3.23" (82mm) of precipitation is typically accumulated. In Portsmouth, during the entire year, the rain falls for 148.1 days and collects up to 29.65" (753mm) of precipitation.Snowfall
January through March, May, November and December are months with snowfall. In Portsmouth, in December, during 3.8 snowfall days, 1.38" (35mm) of snow is typically accumulated. Throughout the year, there are 22.9 snowfall days, and 8.78" (223mm) of snow is accumulated.Daylight
With an average of 9h and 12min of daylight, December has the shortest days of the year.On the first day of the month, sunrise is at 6:52 am and sunset at 4:15 pm. On the last day of December, sunrise is at 7:11 am and sunset at 4:24 pm EST.
Sunshine
In December, the average sunshine is 4.9h.UV index
The months with the lowest UV index are January through March and December, with an average maximum UV index of 2. A UV Index reading of 2, and below, represents a low threat to health from unsafe exposure to UV radiation for average individuals.Note: In December, the maximum UV index of 2 suggests these recommendations:
Although the majority can endure up to an hour in the sun without burns, children always require sun protection. Limiting exposure to the direct Sun during midday hours can help prevent harmful UV radiation effects. On days when the sun blazes, arm yourself with sunglasses that block UVA and UVB radiation. On your guard! Snow's reflection can almost double the intensity of the Sun's UV radiation.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Is it cold in Portsmouth during December?
What is the average humidity in December?
How much does it rain in Portsmouth in December?
How many days does it snow in December?
What is the month with the shortest days?
How many hours of daylight does Portsmouth have in December?
What time are sunrise and sunset in December?
How long on average sun shines in December?
When is the lowest UV index?
What is the UV index intensity in December?
Average temperature in December
Portsmouth, RI
- Average high temperature in December: 42.4°F
The warmest month (with the highest average high temperature) is July (78.3°F).
The month with the lowest average high temperature is January (36.1°F).
- Average low temperature in December: 33.1°F
The month with the highest average low temperature is July (66.7°F).
The coldest month (with the lowest average low temperature) is January (26.4°F).
Average pressure in December
Portsmouth, RI
- Average pressure in December: 30.03"Hg
The month with the highest atmospheric pressure is November (30.07"Hg).
The month with the lowest atmospheric pressure is June (29.93"Hg).
Average wind speed in December
Portsmouth, RI
- Average wind speed in December: 11.6mph
The windiest month (with the highest average wind speed) is January (12.1mph).
The calmest month (with the lowest average wind speed) is August (8.1mph).
Average humidity in December
Portsmouth, RI
- Average humidity in December: 75%
The month with the highest relative humidity is June (81%).
The month with the lowest relative humidity is March (73%).
Average rainfall in December
Portsmouth, RI
- Average rainfall in December: 3.23"
The wettest month (with the highest rainfall) is October (3.27").
The driest month (with the least rainfall) is September (1.42").
Average rainfall days in December
Portsmouth, RI
- Average rainfall days in December: 11.5 days
The month with the highest number of rainy days is April (15.6 days).
The month with the least rainy days is January (8.3 days).
Average snowfall in December
Portsmouth, RI
- Average snowfall in December: 1.38"
The month with the highest snowfall is February (2.76").
The months with the least snowfall are April, June, July, August, September and October (0").
Average snowfall days in December
Portsmouth, RI
- Average snowfall days in December: 3.8 days
The month with the highest number of snowfall days is January (6.6 days).
The months with the least snowfall days are June, July, August, September and October (0 days).
Average daylight in December /
Average sunshine in December
Portsmouth, RI
- Average daylight in December: 9h and 1min
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 12min).
- Average sunshine in December: 4h and 5min
The month with the most sunshine is August (Average sunshine: 10h and 30min).
The month with the least sunshine is February (Average sunshine: 4h and 48min).
Average sunshine days in December
Portsmouth, RI
- Average sunshine days in December: 15.5 days
The month with the most sunshine days is November (17.7 days).
The month with the least sunshine days is April (12.3 days).
Average UV index in December
Portsmouth, RI
- Average UV index in December: 2
The months with the highest UV index are June, July and August (UV index 6).
The months with the lowest UV index are January, February, March and December (UV index 2).
Average cloud cover in December
Portsmouth, RI
- Average cloud cover in December: 47
The month with the most cloud cover is March (Cloud cover 48).
The month with the least cloud cover is August (Cloud cover 29).
Average visibility in December
Portsmouth, RI
- 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, Rhode Island, USA
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