December weather forecast
Portsmouth, United Kingdom

December, the first month of the winter in Portsmouth, is still a chilly month, with an average temperature fluctuating between 8.7°C (47.7°F) and 3.8°C (38.8°F).

Temperature

Portsmouth, United Kingdom, registers an average high-temperature of a chilly 8.7°C (47.7°F) at the commencement of December, closely related to the preceding month. Portsmouth notes a consistent average low-temperature of 3.8°C (38.8°F) during December nights.

Rainfall

In December, in Portsmouth, the rain falls for 11.2 days. Throughout December, 84mm (3.31") of precipitation is accumulated. Throughout the year, there are 103.4 rainfall days, and 699mm (27.52") of precipitation is accumulated.

Sea temperature

In Portsmouth, in December, the average water temperature is 11.8°C (53.2°F).
Note: 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.

Daylight

With an average of 8h and 0min of daylight, December has the shortest days of the year in Portsmouth.
On the first day of December in Portsmouth, United Kingdom, sunrise is at 7:45 am and sunset at 4:01 pm. On the last day of the month, sunrise is at 8:06 am and sunset at 4:08 pm GMT.

Sunshine

With an average of 2h of sunshine, December has the least sunshine of the year in Portsmouth.

UV index

The 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 estimate of 2, and below, represents a low threat to health from unsafe exposure to UV radiation for the ordinary person.
Note: The maximum UV index, 1 during December, leads to the following recommendations:
Infants, children, and people with sensitive skin should always have protection against lengthy periods of sun exposure. Avoiding direct sun during mid-day hours can prevent harmful UV radiation exposure. 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.