Portsmouth
United Kingdom
Long-term weather forecast
Long-term weather forecast

December weather forecast and climate
Portsmouth, United Kingdom

The first month of the winter, December, is still a chilly month in Portsmouth, United Kingdom, with temperature in the range of an average low of 3.8°C (38.8°F) and an average high of 8.7°C (47.7°F).

Temperature

In Portsmouth, the average high-temperature in December is almost the same as in November - a chilly 8.7°C (47.7°F). The average low-temperature, in December, is 3.8°C (38.8°F).

Rainfall

In Portsmouth, in December, it is raining for 11.2 days, with typically 83.9mm (3.3") of accumulated precipitation. In Portsmouth, during the entire year, the rain falls for 103.4 days and collects up to 699mm (27.5") of precipitation.

Sea temperature

In December, the average sea temperature is 11.8°C (53.2°F).
Note: Swimming in 11.8°C (53.2°F) is considered life-threatening. Even a few minutes in 13°C (55.4°F) water is uncomfortable, and swimming below 10°C (50°F) may cause total loss of breathing control and cold shock, depending on a person's physique.

Daylight

With an average of 8h of daylight, December has the shortest days of the year in Portsmouth, United Kingdom.

Sunshine

The month with the least sunshine is December, with an average of 2h of sunshine.

UV index

Months with the lowest UV index in Portsmouth are January, February, November and December, with an average maximum UV index of 1. A UV Index of 2, and less, symbolizes a minimal health hazard from unprotected exposure to the Sun's UV rays for the ordinary person.
Note: In December, the average maximum UV index of 1 translate into the following recommendations:
Most people can stay in the Sun for up to 1 hour without burning, apart from children that always must be protected from sun exposure. The Sun's most intense and consequently most harmful UV radiation during midday hours should be decreased by minimizing exposure and seeking shade. Sun-protective clothing, a long-sleeved shirt and pants, a wide-brimmed hat, and UVA and UVB-blocking sunglasses are particularly helpful in blocking UV radiation's harmful effects.

What is the temperature in December in Portsmouth?

The average high-temperature, in December, in Portsmouth, United Kingdom, is 8.7°C (47.7°F), while the average low-temperature is 3.8°C (38.8°F).

How much does it rain in Portsmouth in December?

In Portsmouth, in December, during 11.2 rainfall days, 83.9mm (3.3") of precipitation is typically accumulated.

How cold is the water in December in Portsmouth?

In Portsmouth, United Kingdom, in December, the average water temperature is 11.8°C (53.2°F). Swimming in 11.8°C (53.2°F) is considered dangerous. Unprotected immersion in temperatures below 10°C (50°F) causes quickly maximum intensity cold shock with hyperventilation.

What is the month with the shortest days in Portsmouth?

December has the shortest days of the year, with an average of 8h of daylight.

How many hours of daylight does Portsmouth have in December?

The average length of the day in December in Portsmouth, United Kingdom, is 8h.

What is the month with the least sunshine in Portsmouth?

December has the least sunshine of the year, with an average of 2h of sunshine.

How long on average sun shines in December in Portsmouth?

In December, the average sunshine in Portsmouth is 2h.

What are the months with the lowest UV index in Portsmouth?

Months with the lowest UV index are January, February, November and December, with an average maximum UV index of 1.

How high is the UV index in December in Portsmouth?

In December, the average daily maximum UV index in Portsmouth, United Kingdom, is 1. A UV Index of 2, and less, symbolizes a minimal health vulnerability from unprotected exposure to the UV radiation.
Average temperature in December - Portsmouth, United Kingdom
  • Average high temperature in December: 8.7°C

Warmest months (with the highest average high temperature) are July and August (21.4°C).
Months with the lowest average high temperature are January and February (8.2°C).

  • Average low temperature in December: 3.8°C

The month with the highest average low temperature is August (14.3°C).
The coldest month (with the lowest average low temperature) is February (2.8°C).

Average rainfall in December - Portsmouth, United Kingdom
  • Average rainfall in December: 83.9mm

The wettest month (with the highest rainfall) is October (86.2mm).
The driest month (with the lowest rainfall) is June (42mm).

Average rainfall days in December - Portsmouth, United Kingdom
  • Average rainfall days in December: 11.2 days

Months with the highest number of rainy days are January and December (11.2 days).
The month with the lowest number of rainy days is July (5.4 days).

Average sea temperature in December - Portsmouth, United Kingdom
  • Average sea temperature in December: 11.8°C

The best month for swimming (with the highest average sea temperature) is September (17.3°C).
The coldest month (with the lowest average sea temperature) is March (8.6°C).

Average daylight in December / Average sunshine in December - Portsmouth, United Kingdom
  • Average daylight in December: 8h

The month with the longest days is June (Average daylight: 16.4h).
The month with shortest days is December (Average daylight: 8h).

  • Average sunshine in December: 2h

The month with most sunshine is July (Average sunshine: 8.4h).
The month with least sunshine is December (Average sunshine: 2h).

Average UV index in December - Portsmouth, United Kingdom
  • Average UV index in December: 1

Months with the highest UV index are May, June, July and August (UV index 6).
Months with the lowest UV index are January, February, November and December (UV index 1).