Weather in Cartagena in December

A good month. December works. It is not the peak, but nothing about it fights you. Highs average 29.5 °C, lows 26.5 °C, and rain falls on 7 days — nothing in the month is working against you.

December ranks 4 of 12 in Cartagena: past the worst of the year but short of January, which is the month to book if the dates are open.

Rain on 7 days, 2 of them heavy. Enough to need a plan B, not enough to need a plan around it. Pack for 29.5 °C days and 26.5 °C nights; the spread matters more here than any single number.

What the averages hide

Averages flatten a month, and this one hides a few things: 9 days top 30 °C — hot spells arrive, but they break; the day barely swings — 3 °C between the overnight low and the afternoon high. Across the twenty years measured, the hottest December day reached 32.7 °C and the coldest night fell to 24.7 °C, and the wettest single day dropped 44 mm — roughly 79% of the month's rain in one day.

This is the volatile part. December rainfall has ranged from 1 mm to 252 mm across the twenty years measured — a 251 mm spread around an average of 56 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 sits around 19 km/h — a steady breeze rather than a nuisance, and welcome on the warmer days, and humidity runs at 81%, high enough to notice on the warm days without dominating them.

How December sits in the year

Temperatures hold steady either side: 29.1 °C in November, 29.5 here, 29.6 in January. Nothing about the timing within the month matters much. Rain is the thing that moves: January brings 6 days less of it, so pushing the dates later buys drier weather.

Daylight in December

Cartagena sits close enough to the equator that daylight barely moves all year — 11.5 hours in December, against a range of just 1.2 hours across the whole calendar. Sunrise and sunset land at roughly the same time whenever you come.

Sea temperature

The sea sits at about 28.4 °C in December — warm enough that the water offers no relief from the heat. The sea peaks at 29.3 °C in October and bottoms out at 27.1 °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

Busy. Popular without being frantic; book the things you care about, improvise the rest.

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

December in Cartagena versus nearby

If Cartagena is one option among several, the nearby comparison is worth making. Barranquilla is close enough to be a coin toss — within a degree on temperature, 1 day less rain. Medellín is the weaker option in December — 5.4 °C cooler, 16 days more rain.

So: December works, with January the better month by 13 points if the dates can move. If they cannot, nothing here should stop you booking.

Every month in Cartagena

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