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South Korea has the dubious distinction of having the coldest temperatures at its latitude so unless you enjoy multi-layer clothing, stick to the months from May to September. On the up side, Korean winters tend to have an abundance of blue skies. Rain is moderate to quite heavy in July and when mixed with high 20°C (78-85°F) days can make things a bit sticky. Whether you enjoy the steamy summer or the crisp winter will depend on your temperament.
