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 shift to December brings a decrease in the average high-temperature, falling from a frosty 46.2°F (7.9°C) in November to a cold 32.2°F (0.1°C). During December, Portsmouth witnesses a consistent average low-temperature of 20.8°F (-6.2°C).Humidity
In Portsmouth, the average relative humidity in December is 79%.Rainfall
In December, the rain falls for 4.2 days. Throughout December, 0.71" (18mm) of precipitation is accumulated. In Portsmouth, during the entire year, the rain falls for 113.5 days and collects up to 15.71" (399mm) of precipitation.Snowfall
January through May, October through December are months with snowfall. In Portsmouth, during December, snow falls for 6.1 days and regularly aggregates up to 1.06" (27mm) of snow. In Portsmouth, during the entire year, snow falls for 31.5 days and aggregates up to 7.13" (181mm) of snow.Daylight
With an average of 9h and 12min of daylight, December has the shortest days of the year in Portsmouth.On the first day of December in Portsmouth, sunrise is at 7:30 am and sunset at 4:52 pm. On the last day of the month, sunrise is at 7:48 am and sunset at 5:01 pm CST.
Sunshine
The average sunshine in December in Portsmouth is 4.8h.UV index
January, February, October through December, with an average maximum UV index of 2, are months with the lowest UV index. A UV Index estimate of 2, and below, represents a low health risk from exposure to the Sun's UV radiation for the average person.Note: A daily high UV index of 2 in December leads to these guidelines:
Extended time in the sun generally does not harm most, but those with sensitive skin, infants, and children should always be protected. To avoid the Sun's strongest rays, limit exposure around the mid-day period. In the presence of strong sunlight, it's crucial to wear sunglasses that ward off UVA and UVB rays. Beware! The strength of the UV rays is increased nearly double-fold by the reflection of the snow.
Frequently asked questions
How cold is it in Portsmouth in December?
What is the average humidity in December in Portsmouth?
How much does it rain in Portsmouth in December?
How many days does it snow in December in Portsmouth?
What is the month with the shortest days in Portsmouth?
How many hours of daylight does Portsmouth have in December?
When is the sunrise / sunset in December in Portsmouth?
How long on average sun shines in December in Portsmouth?
What is the month with the lowest UV index in Portsmouth?
How high is the UV index in December in Portsmouth?
Average temperature in December
Portsmouth, IA
- Average high temperature in December: 32.2°F
The warmest month (with the highest average high temperature) is July (82.6°F).
The month with the lowest average high temperature is January (27.3°F).
- Average low temperature in December: 20.8°F
The month with the highest average low temperature is July (64.9°F).
The coldest month (with the lowest average low temperature) is January (14.5°F).
Average pressure in December
Portsmouth, IA
- Average pressure in December: 30.13"Hg
The month with the highest atmospheric pressure is January (30.16"Hg).
The month with the lowest atmospheric pressure is June (29.87"Hg).
Average wind speed in December
Portsmouth, IA
- Average wind speed in December: 10.1mph
The windiest month (with the highest average wind speed) is April (10.9mph).
The calmest month (with the lowest average wind speed) is July (7.2mph).
Average humidity in December
Portsmouth, IA
- Average humidity in December: 79%
The month with the highest relative humidity is January (83%).
The month with the lowest relative humidity is October (68%).
Average rainfall in December
Portsmouth, IA
- Average rainfall in December: 0.71"
The wettest month (with the highest rainfall) is June (2.64").
The driest month (with the least rainfall) is January (0.43").
Average rainfall days in December
Portsmouth, IA
- Average rainfall days in December: 4.2 days
The month with the highest number of rainy days is June (16.1 days).
The month with the least rainy days is February (2.8 days).
Average snowfall in December
Portsmouth, IA
- Average snowfall in December: 1.06"
The month with the highest snowfall is February (2.09").
The months with the least snowfall are June, July, August and September (0").
Average snowfall days in December
Portsmouth, IA
- Average snowfall days in December: 6.1 days
The month with the highest number of snowfall days is January (8.3 days).
The months with the least snowfall days are June, July, August and September (0 days).
Average daylight in December /
Average sunshine in December
Portsmouth, IA
- 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 July (Average sunshine: 10h and 24min).
The month with the least sunshine is January (Average sunshine: 4h and 30min).
Average sunshine days in December
Portsmouth, IA
- Average sunshine days in December: 21.6 days
The month with the most sunshine days is December (21.6 days).
The month with the least sunshine days is June (11.4 days).
Average UV index in December
Portsmouth, IA
- 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, October, November and December (UV index 2).
Average cloud cover in December
Portsmouth, IA
- Average cloud cover in December: 48
The month with the most cloud cover is January (Cloud cover 52).
The month with the least cloud cover is July (Cloud cover 27).
Average visibility in December
Portsmouth, IA
- 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, Iowa, USA
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