Seoul is classed as having a humid continental/subtropical transitional climate with four distinct seasons. Temperature differences between the hottest part of summer and the depths of winter are extreme. Summer (June to August) brings hot, humid weather with average high temperatures soaring as high as 85°F (29°C) on occasion; in winter (December to February) average low temperatures drop as low as 21°F (-6°C). The most pleasant seasons in the city are spring and autumn, when blue skies and comfortable temperatures are a sure bet. The city experiences heavy rainfall, but most of it falls in the summer monsoon period between June and September.