Weather in Lisbon in December

How December compares

December is the 10th warmest month of the year in Lisbon and ranks 87th of 134 destinations we compare for December - see where else is hot in December. Within Portugal it is 12th of 13 (Portugal in December). Against London's average high of 7.7°C in December, Lisbon is 6.8°C warmer by day and 7.5°C warmer at night.

Daytime and night-time in December

The typical December day in Lisbon peaks at 14.5°C, but that is an average: the warmest 10% of days reach 16.6°C or more. Days over 25°C are rare. Nights average 10.2°C; one night in ten drops to 6.6°C or lower, so pack a layer for evenings - it is genuinely cool after dark. Between 1991 and 2020 the hottest December day here reached 19.8°C (2018-12-06) and the coldest night 3.0°C (2009-12-20).

Rain in December

Wet (more than 8 rainy days): about 9 days with 1 mm or more, 79 mm in total. Year to year it varies a lot - the wettest December was 2000 with 214 mm, the driest 1993 with 5 mm. Humidity averages 82%.

Sea temperature in December

The sea averages 15.2°C - too cold for most (under 18°c). Depending on the year it ranges from 14.7°C to 15.9°C. For the warmest sea here, come in August (19.2°C).

Sunshine and daylight

Around 4.1 hours of sunshine a day (estimated from cloud cover), 9.3 hours of daylight: the sun rises about 07:48 and sets about 17:16 local time in mid-December. Average cloud cover is 56%.

Is December a good time to visit Lisbon?

December is not the strongest month here: cool days and frequent rain. The best months for Lisbon on our scoring are July, August, September; months averaging 25°C or more: Jul, Aug.

Milder than London, but still coat weather

Lisbon’s average December high is 6.8°C above London’s, so the daytime difference is meaningful without making it a warm-weather holiday. Nights average 10.2°C, and the coldest 10% fall to 6.6°C or below. Pack layers, a jacket and something warmer for evenings rather than relying on a light jumper throughout the trip. The warmest 10% of days reach at least 16.6°C, which can make time outdoors more comfortable, but those milder spells are a bonus rather than a packing plan. This weather suits travellers who prefer walking in cool conditions and do not need much heat to enjoy being outside.

Keep outdoor plans flexible

December is wet enough that a waterproof outer layer and shoes you are comfortable wearing in rain should earn their space in your bag. About 9 days receive measurable rain, so do not build the trip around uninterrupted dry weather. Equally, that figure does not mean every wet day is lost to rain. With 9.3 hours of daylight and about 4.1 hours of sunshine, make daylight your priority for outdoor plans and leave room to change their order. Check the forecast before committing to a long spell outside. December works best if you can enjoy a dry window without needing the whole day to stay clear.