The main characteristics of the general atmospheric circulation in spring 2020 (from March to May) are as follows. The polar vortex is characterized by a monopole pattern in the Northern Hemisphere and is stronger than average. The westerlies in the middle and high latitudes are in three-wave pattern. In March, the cold air that influenced China is frequent but not strong and has greater impact on the northern seas. In April, the atmospheric circulation over offshore areas of China is in meridional pattern, which is favorable for the southward of the cold air. In May, the cold air is weaker and extratropical cyclone activities increase. There are 13 gale processes above 8 grade over offshore areas of China, including 4 produced by cold air, 5 jointly by cold air and extratropical cyclones, and 4 by extratropical cyclones. Seven obvious sea fog processes occur over offshore areas, including three in March, one in April, and three in May. There are 10 rough sea wave processes above 2 m and days of rough sea wave processes are less. One tropical cyclones is active over western North Pacific and the South China Sea. The sea surface temperature in the offshore areas shows upward tendency, while the temperature rising rate in the northern seas is larger than that in the southern seas.