Weather in Busan in December

A hard month. December is a hard month in Busan, and worth planning around. Highs sit at 8.1 °C and the day is short; this is an indoors-with-excursions month, not an outdoors-all-day one.

December ranks 11 of 12 — near the bottom of Busan's year. October is the month that works, and the swing between the two is 42 points, which is a different holiday rather than a slightly better one.

Rain falls on only 4 days, so an itinerary with no wet-weather fallback is a reasonable risk. Layers, and a genuinely waterproof outer — at 8.1 °C the difference between a good day and a miserable one is entirely down to what you are wearing.

What the averages hide

Averages flatten a month, and this one hides a few things: 12 nights fall below freezing. Across the twenty years measured, the hottest December day reached 18.6 °C and the coldest night fell to -9.1 °C, and the wettest single day dropped 55 mm — roughly 172% of the month's rain in one day.

This is the volatile part. December rainfall has ranged from 5 mm to 109 mm across the twenty years measured — a 104 mm spread around an average of 32 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 15.1 km/h, so the temperature on the page is close to the temperature on your skin, and humidity runs at 77%, which at 8.1 °C means damp rather than muggy — the kind of cold that gets into a coat and stays there.

How December sits in the year

The month is on the way down: 6.6 °C cooler than November, with January dropping another 2 °C. The first week and the last are not the same trip.

Daylight in December

December sits at the dark end of Busan's year — 9.8 hours of daylight against 14.5 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 17.5 °C in December — cold — a quick dip rather than a swim, and a wetsuit if you are in for longer. The sea peaks at 26.9 °C in August and bottoms out at 13.9 °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

Off season. The genuine off season: cheapest by a distance, with the caveat that some tours and restaurants close entirely.

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

December in Busan versus nearby

If Busan is one option among several, the nearby comparison is worth making. Daegu is the weaker option in December — 2.7 °C cooler, the same number of rain days. Gwangju is close enough to be a coin toss — within a degree on temperature, 3 days more rain.

So: December is a compromise. October is 41 points better and is what Busan is actually like at its best — worth moving the trip for if that is possible, and worth adjusting expectations for if it is not.

Every month in Busan

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