The Korean peninsula is located mid-latitude in the Northern Hemisphere and lies in the transitional zone between continental and subtropical maritime climates. Like North America it has four distinct seasons, though the climate varies a bit between the northern and southern parts of the country.
Spring: Spring begins in late March and ends in May. It rains occasionally, but is most notably marked by the blooming of cherry blossoms all over the peninsula. Koreans usually flock in great numbers to parks and famous streets where these trees are found in abundance.
Summer: Extending from June to early September, Korean summers are hot and extremely humid. Half of the total annual rainfall occurs during the monsoon months of late June and July. Mosquitoes and other insect life thrive during this time, and if you are unlucky enough to not have an air-conditioner in your apartment, the nights can get quite long, sticky and bug-ridden. Fortunately, second-hand air-conditioners are abundant and cheap.
Autumn: Running roughly from September through November, Korean autumn is usually the most pleasant season. Very little rain falls during this time, and the days and nights are usually clear and calm. This is a great time to head to the mountains for hiking and to take in the fresh air and view the changing colors of the leaves.
Winter: Winter extends from December to mid-March and generally follows a cycle of three cold days followed by four warmer ones. Snow may be heavy in the mountain regions in the north and east of the country, but is usually quite negligible in the major cities. The temperature rarely drops below -10 Celsius in the city, and any snow that does fall is usually gone within a day or two at the most.