Weather in Busan in January

A hard month. January is a hard month in Busan, and worth planning around. Highs sit at 6.1 °C and the day is short; this is an indoors-with-excursions month, not an outdoors-all-day one.

January ranks 12 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 6.1 °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: 16 nights fall below freezing. Across the twenty years measured, the hottest January day reached 16.8 °C and the coldest night fell to -10.8 °C, and the wettest single day dropped 41 mm — roughly 137% of the month's rain in one day.

This is the volatile part. January rainfall has ranged from 1 mm to 109 mm across the twenty years measured — a 108 mm spread around an average of 30 mm. The average is real but almost no individual January looks like it, so treat the figure as the middle of a wide range rather than a forecast.

Wind is light at 15.6 km/h, so the temperature on the page is close to the temperature on your skin, and humidity runs at 76%, which at 6.1 °C means damp rather than muggy — the kind of cold that gets into a coat and stays there.

How January sits in the year

This is a turning point in the year — December and February sit on opposite sides of it, so the month contains the change rather than following it.

Daylight in January

January sits at the dark end of Busan's year — 10 hours of daylight against 14.5 at midsummer, gaining 0.6 hours across the month. Sightseeing days are genuinely shorter, and an itinerary built for summer will not fit.

Sea temperature

The sea sits at about 15.1 °C in January — 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.

January in Busan versus nearby

If Busan is one option among several, the nearby comparison is worth making. Daegu is the weaker option in January — 2.6 °C cooler, the same number of rain days. Gwangju is the weaker option in January — within a degree on temperature, 2 days more rain.

So: January is a compromise. October is 42 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 January.