Weather in Busan

Busan is in South Korea at 35.1°N. The 2001–2020 NASA POWER daily record describes a continental climate with a wide temperature swing. August is the warmest month (average 25.9°C, high 28.2°C) and January is the coolest (average 2.5°C, low -0.8°C).

Rain is wet season runs from April to September, inside an annual total of 1488 mm. The wettest month is July at 299 mm; the driest is January at 30 mm. On this site the months that score closest to a 22°C day, lighter rain, and moderate humidity are June, July, and September.

How warm Busan gets

Monthly average highs run from 5.8°C in January to 28.2°C in August. Nights follow the same curve: -0.8°C in January and 23.6°C in August.

Mean high across all twelve months is 17.4°C and mean low is 10.9°C. These are 20-year grid averages, so a city station can read a few degrees warmer or cooler.

When Busan gets wet

The wet season in Busan starts in April and ends in September (April, May, June, July, August, and September). July is the core of it at 299 mm. January is the other extreme, with 30 mm.

A rainy day here is a day with at least 1 mm in the NASA POWER series. July averages 17 such days; January averages 4.

Distinctive months in Busan

January is the coolest month, with lows around -0.8°C and highs near 5.8°C. Rainfall is 30 mm. February brings 52 mm and 5 rainy days; temperatures run from 0.8°C to 8.0°C. March stands apart from the months beside it: 11.9°C / 3.9°C and 79 mm. The wet season opens in April. Expect 137 mm and 8 rainy days, with nights around 8.5°C. In May, Busan averages 20.8°C by day and 13.3°C at night, with 144 mm of rain. June brings 175 mm and 10 rainy days; temperatures run from 17.8°C to 23.9°C.

July is the wettest month — 299 mm and 17 rainy days, with 89% humidity. Peak heat arrives in August: 28.2°C by day, 23.6°C at night, and 85% humidity. September closes the wet season: 175 mm over 11 rainy days, then the calendar dries. In October, Busan averages 20.3°C by day and 13.4°C at night, with 75 mm of rain. November: 14.3°C high, 7.2°C low, 46 mm rain, 75% humidity. December stands apart from the months beside it: 7.8°C / 1.1°C and 33 mm.

Best months to visit Busan

The three months with the highest comfort score are June, July, and September: June (20.9°C average, 175 mm, 83% humidity); July (24.3°C average, 299 mm, 89% humidity); September (22.1°C average, 175 mm, 82% humidity). They fall in calendar order. The score rewards averages near 22°C, lower rainfall, and humidity near 60%. It is a climate score, not a festival or price calendar.

If you want the wet season itself — fewer crowds, greener landscape, heavier rain — aim at April–September instead of the score.

How Busan compares inside South Korea

Daegu is about 94 km away: Busan is 1.1°C warmer than Daegu in its hottest month and 287 mm wetter over the year than Daegu. Daegu’s wettest month is July (264 mm) versus July here.

Gwangju is about 192 km away: Busan is 0.6°C warmer than Gwangju in its hottest month and 107 mm wetter over the year than Gwangju. Gwangju’s wettest month is July (290 mm) versus July here.

Daejeon is about 203 km away: Busan is 1.1°C warmer than Daejeon in its hottest month and 263 mm wetter over the year than Daejeon. Daejeon’s wettest month is July (316 mm) versus July here.