The East Asian monsoon is a seasonal weather pattern that significantly influences the climate of countries like China, Japan, and Korea. It is characterized by a shift in wind direction, bringing moist air from the ocean during the summer months, which results in heavy rainfall. This monsoon typically occurs from June to September, providing essential water for agriculture. In contrast, during the winter months, the monsoon reverses, bringing cold, dry air from the north. This seasonal change affects temperature and precipitation levels, leading to distinct wet and dry seasons. The East Asian monsoon is crucial for the region's ecosystems and agricultural productivity.