In 2011, unusual ocean and atmospheric patterns affected China's climate. The La Nina event in the Pacific Ocean and changes in the subtropical high pressure system led to less rain and higher temperatures. The Indian Ocean also experienced abnormal temperature patterns. The winter monsoon was stronger than usual, while the summer monsoon was normal. The South China Sea monsoon was weaker, starting and ending later. Overall, fewer tropical cyclones occurred in the South China Sea and West Pacific in 2011.