Weather in Barcelona in December

A good month. December works. It is not the peak, but nothing about it fights you. Highs sit at 15 °C and the day is short; this is an indoors-with-excursions month, not an outdoors-all-day one.

December ranks 9 of 12 in Barcelona: past the worst of the year but short of April, which is the month to book if the dates are open.

Rain falls on only 5 days, so an itinerary with no wet-weather fallback is a reasonable risk. Layers, and a genuinely waterproof outer — at 15 °C the difference between a good day and a miserable one is entirely down to what you are wearing.

What the averages hide

The averages here are honest — no hidden extremes worth planning around. Across the twenty years measured, the hottest December day reached 21.5 °C and the coldest night fell to -1 °C, and the wettest single day dropped 97 mm — roughly 313% of the month's rain in one day.

This is the volatile part. December rainfall has ranged from 2 mm to 122 mm across the twenty years measured — a 120 mm spread around an average of 31 mm. The average is real but almost no individual December looks like it, so treat the figure as the middle of a wide range rather than a forecast.

Wind is light at 8.3 km/h, so the temperature on the page is close to the temperature on your skin, and humidity runs at 76%, high enough to notice on the warm days without dominating them.

How December sits in the year

Temperatures hold steady either side: 18.4 °C in November, 15 here, 14.6 in January. Nothing about the timing within the month matters much.

Daylight in December

December sits at the dark end of Barcelona's year — 9.2 hours of daylight against 15.1 at midsummer, holding steady all month. Sightseeing days are genuinely shorter, and an itinerary built for summer will not fit.

Sea temperature

The sea sits at about 15.4 °C in December — cold — a quick dip rather than a swim, and a wetsuit if you are in for longer. The sea peaks at 25.5 °C in August and bottoms out at 13.2 °C — water lags the air by a month or two, which is why the best swimming often comes after the best weather.

How busy it gets

Shoulder. The value months — prices ease off and you get the place closer to itself.

Crowd levels are estimated from climate desirability and school-holiday calendars, not from visitor numbers.

December in Barcelona versus nearby

If Barcelona is one option among several, the nearby comparison is worth making. Palma is close enough to be a coin toss — within a degree on temperature, 3 days more rain. Toulouse is the weaker option in December — 4.4 °C cooler, 7 days more rain.

So: December works, with April the better month by 11 points if the dates can move. If they cannot, nothing here should stop you booking.

Every month in Barcelona

See all twelve months in Barcelona, or where else to go in December.