<Li> Typhoon season occurs from July through September . About once each year, a typhoon passes very close to or moves over Korea, causing heavy showers . </Li> <P> As a temperate climate, Seoul has winter, spring, summer and autumn seasons . The monsoon season and typhoons also occurs in the summer season . </P> <P> The winter in Seoul is controlled by the large Siberian high pressure system (the Asiatic high), which results in predominantly cold, dry north - westerly winds . The influence of the Siberian high leads to significantly colder winter temperatures than would be expected at this latitude . About every 4 to 6 days a low - pressure trough will move through South Korea, bringing with it cloudiness and light precipitation . The amount of precipitation locally depends mostly on the elevation of the station and the length of time that the air has been over the Yellow Sea . Maximum snowfall occurs over the northwest coast, which is the most exposed to the northwesterly flow, and in the mountain areas . Normally less than 10 percent of the annual precipitation falls during the winter . Frequently the weather is cloudless, clear, and dry, except for the southwestern region of the peninsula . The mean January temperature in Seoul is - 2.4 ° C (27 ° F). January, is the coldest month in Seoul . </P> <P> During the summer, East Asian monsoon winds engulf the city and the warm, moisture laden air moving off the oceans clashes with the drier air to the north . These fronts oscillate back and forth across Korea during the summer months . The interior highlands disturb the winds, forcing them into a westerly / southwesterly direction . The majority of the annual precipitation falls between late June and the middle of September, with rains fully developing along the entire peninsula by mid-June . Seoul receives approximately 126 mm (5 in) of precipitation during the winter (December--March), but in July alone receives approximately 383 mm (14.3 in). July is the wettest month in the metropolis . </P>

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