December weather forecast
Lisbon, Portugal

During December, Lisbon finally succumbs to winter, with temperatures hitting near-year lows at around 15.3°C. Despite experiencing substantial rainfall at 127mm, Lisbon retains its charm, morphing into a winter wonderland under the Mediterranean sun. The days are at their shortest, with daylight hours dropping to a mere 9.5 hours, signaling the onset of winter festivities. With the lowest sea temperatures of the year, beach activities come to a standstill, shifting the focus to shopping, indoor entertainment, and holiday events.

Temperature

The transition from November to December in Lisbon brings an average high-temperature of a still refreshing 15.3°C, barely different from November's 18.2°C. During December, the average low-temperature in Lisbon is a frosty 9.4°C.

Rainfall

In December, the rain falls for 14 days. Throughout December, 127mm of precipitation is accumulated. In Lisbon, during the entire year, the rain falls for 112 days and collects up to 774mm of precipitation.

Sea temperature

In Lisbon, the average seawater temperature in December is 16.6°C.
Note: For the majority of people, swimming in water at 16.6°C is not enjoyable. The challenge of controlling breathing escalates as the temperature decreases from 21°C to 15°C.

Daylight

December has the shortest days of the year in Lisbon, with an average of 9h and 30min of daylight.
On the first day of the month, sunrise is at 07:35 and sunset at 17:15. On the last day of December, sunrise is at 07:54 and sunset at 17:24 WET.

Sunshine

The months with the least sunshine are January, February, November and December, with an average of 5h of sunshine.

UV index

The months with the lowest UV index in Lisbon are January and December, with an average maximum UV index of 2. A UV Index estimate of 2, and below, represents a minimal health hazard from exposure to the Sun's UV radiation for ordinary individuals.
Note: An average UV index of 2 in December transforms into this advice:
Children necessitate constant protection from sunlight, unlike the majority, who can remain under the sun for about an hour without burning. The Sun's UV radiation is especially harmful around midday, so reduce exposure and stay safe. On bright days sunglasses that block both UVA and UVB rays should be worn. A hat with a wide brim is extremely helpful, as it can prevent roughly 50% of UV radiation from reaching the eyes.