How do monsoon winds affect weather in the South China Sea?

The weather in the South China Sea is tropical and primarily controlled by monsoon winds, which dictate seasonal rainfall patterns, sea-surface currents, and water exchange with adjacent bodies of water.12

• Seasonal Wind Reversal: During the summer (May–September), monsoonal winds blow predominantly from the southwest. In the winter (October–April), the wind direction reverses, blowing from the northeast.32
• Rainfall: The region experiences significant annual rainfall, ranging from approximately 80 inches (2,000 mm) to more than 120 inches (3,000 mm) around the southern basin.2
• Typhoons: Summer typhoons are a frequent and significant weather complication in the region.312
• Hydrological Impact: These winds drive sea-surface currents. For example, the strong southwestern monsoon in summer generates surface flows reaching speeds of up to 3.5 miles (5.6 km) per hour along the coast of Vietnam. Additionally, the winds can cause the displacement of surface water, leading to upwelling areas that result in colder surface temperatures and higher nutrient content.2