What causes South Korea to have cold winters and hot humid summers?

South Korea’s climate is primarily shaped by its proximity to the vast Asian landmass, which creates a continental climate characterized by significant seasonal temperature extremes.1

The cold, dry winters and hot, humid summers are driven by two main factors:

• Continental Influence: Being situated next to the main Asian landmass results in marked temperature differences between the seasons.1
• Monsoon Winds: The northeast Asian monsoons establish the country's precipitation patterns. During the summer months of June through August, these seasonal winds bring heavy rainfall, accounting for up to three-fifths of the annual precipitation.1

While winter temperatures frequently drop below freezing, summer temperatures remain relatively uniform across the country, typically averaging in the high 70s °F (about 25 °C) during the warmest month of August.1