Abstract:Based on the NCEP/NCAR reanalysis datasets and climate observation from 2400 stations of China, the characteristics of climatic anomaly over China in autumn 2024 and the possible causes are analyzed. The results denote that, in autumn 2024, the mean temperature in China peaked the record in the same period since 1961 and the average precipitation was slightly more than the climatic mean, with the spatial distribution generally characterized by “more in the north and less in the south”. In autumn, the typhoons generated in the Northwest Pacific and the landing typhoons in China were more than normal, and their paths were mainly in the northwest direction. The circulation in the mid-high latitudes in East Asia showed the feature of “low in the west and high in the east”. The West Pacific subtropical high (WPSH) was stronger and more westward than usual overall, and its ridge line swung frequently in the meridional direction, that is, the ridge line was abnormally further north than usual in September, slightly north than usual in October and close to normal position in November, which led to the abnormal warming in China. The SST in the West Pacific was higher than normal. The South China Sea and its eastern area were the positive vorticity area with small vertical wind shear, and the significantly higher pseudo-equivalent temperature in the lower level from the northern Philippines to the south of the Sea of Japan, were conducive to the formation of abnormally more typhoons in autumn. The strengthening of convection activity from the maritime mainland to the West Pacific brought by MJO eastward spread from the end of August to September was beneficial to the abnormal northward position of the subtropical high, which made the typhoon track by north in autumn. In addition, the abnormally lower SST in the equatorial Middle East Pacific and the unusually late retreat of the summer monsoon in the South China Sea all contributed to the frequent occurrence and northward track of typhoons in autumn 2024.