Weather in Busan in May

Prime time. If you get to pick your dates, May is the one. Highs average 21.1 °C, lows 13.7 °C, and rain falls on 9 days — nothing in the month is working against you.

May ranks 2 of 12 in Busan. Only October scores clearly higher, and the difference is small enough to be settled by price rather than weather.

Rain on 9 days, 4 of them heavy. Enough to need a plan B, not enough to need a plan around it. Nothing specialised needed — this is the month you pack for the trip rather than for the weather.

What the averages hide

Averages flatten a month, and this one hides a few things: it never really gets hot: not one day in an average May reaches 30 °C. Across the twenty years measured, the hottest May day reached 29.1 °C and the coldest night fell to 6 °C, and the wettest single day dropped 121 mm — roughly 84% of the month's rain in one day.

May is moderately variable: 39 mm in the driest year against 314 mm in the wettest, around an average of 144 mm. Roughly two Mays in three land near that average, and the third does something else entirely.

Wind is light at 11.2 km/h, so the temperature on the page is close to the temperature on your skin, and humidity runs at 79%, high enough to notice on the warm days without dominating them.

How May sits in the year

The month is on the way up: 4.3 °C warmer than April, and June adds another 3.2 °C. Late in the month feels noticeably different from the start of it, which is worth knowing if the trip is short.

Daylight in May

May is at or near the longest days of Busan's year: 14 hours of daylight, gaining 0.8 hours across the month. Evenings are the real gain — dinner outdoors still happens in full light.

Sea temperature

The sea sits at about 17.3 °C in May — 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

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.

May in Busan versus nearby

If Busan is one option among several, the nearby comparison is worth making. Daegu is close enough to be a coin toss — 3.6 °C warmer, 1 day less rain. Gwangju is close enough to be a coin toss — 2.1 °C warmer, 1 day less rain.

So: May works, with October the better month by 9 points if the dates can move. If they cannot, nothing here should stop you booking.

Every month in Busan

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