In winter 2019 (from December 2019 to February 2020), the features of atmospheric circulation are as follows. The polar vortex in the Northern Hemisphere is distributed in a dipole type, the atmospheric circulation shows a three-wave pattern in the middle and high latitudes, and the trough and ridge in the westerlies are significantly weaker than those in normal years. The geopotential height anomaly field shows that the mid-latitude region of East Asia is in a positive anomaly zone, the cold air is weaker, and the gale process is significantly reduced due to the weak East Asia major trough. Seven gale processes stronger than 8 grade are observed in China's offshore waters, two of which are jointly influenced by cold air and extratropical cyclones, and another two gale processes are jointly influenced by cold air and tropical cyclones. There are 10 wave processes above two m. There are 12 large-scale sea fog processes in the coastal waters and sea fog mainly appears in Bohai Sea, Bohai Strait, the northern and central Yellow Sea, Qiongzhou Strait, and Beibu Gulf mostly from night to morning. The sea surface temperature gradually decreases with time and the temperature difference from north to south increases from 22 ℃ to 27 ℃ in winter. One tropical cyclone is active over western North Pacific and the South China Sea.