South Korea - Climate
South Korea tends to have a humid continental climate and a humid subtropical climate, and is affected by the East Asian monsoon, with precipitation heavier in summer during a short rainy season called jangma (장마), which begins end of June through the end of July. Winters can be extremely cold with the minimum temperature dropping below −20 °C (−4 °F) in the inland region of the country: in Seoul, the average January temperature range is −7 to 1 °C (19 to 34 °F), and the average August temperature range is 22 to 30 °C (72 to 86 °F). Winter temperatures are higher along the southern coast and considerably lower in the mountainous interior. Summer can be uncomfortably hot and humid, with temperatures exceeding 30 °C (86 °F) in most parts of the country. South Korea has four distinct seasons; spring, summer, autumn and winter. Spring usually lasts from late-March to early- May, summer from mid-May to early-September, autumn from mid-September to early-November, and winter from mid-November to mid-March.
Rainfall is concentrated in the summer months of June through September. The southern coast is subject to late summer typhoons that bring strong winds and heavy rains. The average annual precipitation varies from 1,370 millimetres (54 in) in Seoul to 1,470 millimetres (58 in) in Busan. There are occasional typhoons that bring high winds and floods.