While precipitation is abundant the entire year in almost the entire state, the coastline tends to have a slightly wetter summer, while inland March tends to be the wettest month. During the cold season, extratropical cyclones is the main cause of precipitation, while during the summer, tropical cyclones and thunderstorms forming due to afternoon heating are the main causes of precipitation. A lee side rain shadow from the Appalachian Mountains lowers annual precipitation across central portions of the state. Inland sections average 40 inches (1,000 mm) to 50 inches (1,300 mm) of rainfall, while near the coast 50 inches (1,300 mm) to 60 inches (1,500 mm), and the Piedmont receives 70 inches (1,800 mm) to 80 inches (2,000 mm) of precipitation. Winter precipitation is determined in large by the El Nino-Southern Oscillation. During El Nino events, the jet stream is further south and east across the U.S., thus leading to cooler and wetter winters in South Carolina, while La Nina keeps the jet stream further north and west causing warmer and drier winters.

is there a rainy season in south carolina?
no