Seoul belongs to the temperate zone featured by four distinctive seasons of spring, summer, autumn and winter.

The yearly average temperature of Seoul is 12.9 degrees C. Temperatures in Seoul tend to fluctuate a great deal, reaching as high as 36.1 degrees C in the summer and dropping as low as -13.7 degrees C in the winter. Influenced by the north Pacific high pressure system, Seoul has hot and humid summers with average temperatures above 20 degrees C from June through September.

During the midsummer period the city often records daily highs of over 30 degrees C. In winter, Seoul is topographically influenced by the expansion of the Siberian high pressure and prevailing west wind with temperatures dropping lower than other regions on the same latitude. The rise and fall of the high pressure system causes a typical cycle of three successive cold days followed by four warmer days, relieving people from freezing temperatures.

The annual precipitation in Seoul averages 1,210.2 mm, which is more than the average amount of rainfall across the peninsula. Most of the rainfall is concentrated in the rainy months (monsoon period) of June through September when downpours account for about 70 % of the total annual precipitation. Except for those rainy spells, however, Seoul boasts fine weather throughout the year and is especially famous for its azure autumn skies.

The Korean flag is called t'aegukki. Its design symbolizes the principles of yin and yang in Oriental philosophy. The circle in the center of the flag is divided into two equal parts. The upper red section represents the positive cosmic forces of yang. Conversely, the lower blue section represents the negative cosmic forces of yin. The two forces together embody the concepts of continual movement and balance and harmony that characterize the sphere of infinity. The circle is surrounded by four trigrams, one in each corner. Each trigram symbolizes one of the four universal elements :

The national flower of Korea is the Mugunghwa or Rose of Sharon. Every year from June to October a profusion of Mugunhwa blossoms grace the entire country. Unlike most flowers, Mugunghwa is remarkably tenacious and is able to withstand both blight and insects. The flower's symbolic significance stems from Mugunghwa's root word, "Mugung," meaning immortality. This word accurately reflects the perseverance and determination of the Korean people that has been demonstrated through out their long history.