In the summer (from June to August) of 2023, the atmospheric circulation features are as follows. In the Northern Hemisphere, the polar vortex exhibits a bipolar distribution with weakened intensity compared to the climate normal. The synoptic mid-latitude circulation at 500 hPa in the Eurasian region and western North Pacific is similar to the climate normal. The subtropical high is located further west and slightly south of its climate normal position with greater intensity and a larger coverage area. In June, the coastal areas in the eastern and northern parts of China experience three processes of sea fog, while there are no extensive sea fog events observed in July and August. Throughout the summer, 10 typhoons are generated over western North Pacific and the South China Sea, which is fewer than the climate normal, with significantly stronger average maximum intensity. More specifically, in June, one turning typhoon is generated offshore; in July, three typhoons form, among which two typhoons make landfall in China; in August, typhoon activity is frequent, 6 typhoons form and two out of them make landfall in China in September. Additionally, there are 20 named tropical cyclones in other sea areas. During the summer, China’s coastal regions experience 6 episodes of severe winds exceeding Beaufort wind force scale 8, and 5 of them attribute to tropical cyclones and one to the Jianghuai cyclone entering the sea. There are 12 occurrences of waves higher than 2.0 m. In the summer, the sea surface temperature in western North Pacific and the South China Sea is generally higher than the climate normal. Typhoon activities significantly influence the distribution pattern of wave height and sea surface temperature.