Korea Weather by Month: Seoul, Busan and Jeju Averages (2026)

A climate normal is a 30-year average. All figures here are KMA normals for 1991–2020, from the stations in Seoul (108), Busan (159) and Jeju City (184), published in the Climatological Normals of Korea.

• Average high and low are the mean daily maximum and minimum for the month.
• Rain is the average monthly total precipitation, including snow measured as water.

A normal is not a forecast. Any single year can be warmer, colder, wetter or drier. Check the KMA forecast in the week before you travel.

Source: KMA climate normals 1991–2020, station 108 (Seoul).

Seoul gets about 63% of its yearly rain in June to August and only about 5% in December to February (KMA). In a typical year, Seoul's first frost comes around 28 October, first ice around 3 November and first snow around 20 November.

Busan and Jeju sit on the south coast and are milder than Seoul in winter. Busan's annual average is 15.0°C and Jeju City's is 16.2°C.

Source: KMA climate normals 1991–2020, stations 159 (Busan) and 184 (Jeju).

Jeju's figures are for Jeju City on the north coast. Weather changes quickly with height on Hallasan, and the mountain is much colder than the coast in winter.

The summer rainy season, 장마jangmaRainy season, normally starts around 19 June in Jeju, 23 June in the south and 25 June in the central region, including Seoul. It lasts about 31 days on the mainland and about 32 days in Jeju (KMA).

Of the roughly 25 typhoons that form in the North Pacific each year, about 3.4 affect Korea directly or indirectly (KMA). If a typhoon is forecast, flights, ferries to islands and outdoor events can be cancelled.

Humidity is highest in July and August and lowest in February and March.

Indoor heating and air conditioning are strong, so dress in layers you can take off.

• Spring (March to May). Mornings are cool and afternoons warm. A light jacket over a T-shirt works for most of April and May. March can still be cold, especially in the evening.
• Summer (June to August). Hot and humid, with heavy rain during the rainy season. Wear breathable clothes and carry a compact umbrella. Bring a thin layer for air-conditioned subways and cafés.
• Autumn (September to November). Clear and dry. September is still warm. By November you need a coat in Seoul.
• Winter (December to February). Cold and dry, often below freezing in Seoul. Wear a warm coat, hat, gloves and shoes with grip for icy pavements. The Korea Tourism Organization advises warm jackets, gloves, scarves and non-slip shoes for snow (VisitKorea).

Banks, government offices and some small businesses close on public holidays. Big holidays also fill trains and roads.

Source: KASI calendar data 2027 and 2026, checked October 2026.

The Korea Tourism Organization names July to August and December to January as peak seasons, when flight prices rise (VisitKorea). Many stores hold sales from June to August and from December to February (VisitKorea).

Seollal and Chuseok are the busiest travel days of the year inside Korea. If your dates overlap, book trains early; see KTX and trains.

• Packing for the average, not the range. In spring and autumn, the daily range is wide. Pack for both the high and the low.
• Rain in July. Plan indoor options, such as museums and markets, for rainy days.
• Ice in January. Pavements and stairs can be slippery. Wear shoes with grip.