In the eastern monsoon region of China, the precipitation in summer belongs to frontal rain, isn't winter frontal rain?

In winter, due to the strengthening of dry and cold air in the north, the whole monsoon region will be completely controlled, and it is not easy to form precipitation due to the influence of single cold air.

The summer precipitation in eastern China is mainly convective rain. There is little frontal rain, and if there is, it is generally cold frontal precipitation, especially in the north and south.

Judging the cold and warm front depends on the difference between the original air mass and the new air mass in a place. In summer, the high temperature in eastern China is generally controlled by tropical marine air masses. In this case, it is impossible to form rainfall through stronger ocean warm and humid airflow. It is more likely to be caused by the cold air in the north going south.