Climate Prediction and Outlook in China for the 2026 Flood Season

In March 2026, the Annual Symposium on China Climate Prediction for the summer season (June–August) was held at the Institute of Atmospheric Physics (IAP), Chinese Academy of Sciences. Currently, the decadal modes of sea surface temperatures (SSTs) indicate the negative phase of the Pacific Decadal Oscillation and the positive phase of the Atlantic Multidecadal Oscillation. Under a transition from a weak La Niña to an El Niño state in the next three to five months, climate anomalies are predicted in China for summer 2026 based on results from various numerical and statistical models developed by the IAP. During the 2026 flood season (June–August), the East Asian summer monsoon may be slightly stronger than normal, the western Pacific subtropical high (WPSH) will be stronger, its western ridge point may extend further westward, and its ridge line might be slightly northward. Seasonally averaged precipitation slightly exceeding normal levels might occur in most parts of Northeast China, eastern North China, the middle and lower reaches of the Yellow River, the Yellow River and Huai River basins, the southeast coastal region of China, eastern Sichuan Province, southern Shaanxi Province, southern Southwest China, and most of Tibet. In particular, rainfall may be 20%–50% higher than normal in central Northeast China and eastern North China, implying a high possibility of local flooding disasters. In contrast, other parts of China may experience drier-than-normal conditions in the coming summer, with precipitation reduced by 20%–50% in the middle and lower reaches of the Yangtze River and northern Xinjiang. Furthermore, more typhoons may make landfall this summer. Due to uncertainty in the evolution trends of SST anomalies in tropical oceans and the limited ability to predict intraseasonal variations of the WPSH, mid-high-latitude atmospheric circulations, and western Pacific warm pool convection, these climate predictions for the 2026 flood season are uncertain to some extent. The authors will conduct supplementary forecasts based on observed variations in atmospheric and oceanic processes in the late spring and early summer of 2026.