Seoul belongs to the Temperate Zone featuring four distinctive seasons of spring, summer, autumn and winter. The annual average temperature is 12.2 degrees Celsius. Temperatures in Seoul experience large seasonal variation, reaching as high as 38.4 degrees Celsius in the summer and dropping as low as minus 19.2 degrees Celsius in the winter. Influenced by the North Pacific high-pressure system, Seoul has hot and humid summers with average temperature above 20 degrees Celsius from June through September.