Generally speaking, in late Grain in Ear period, continuous cloudy and rainy weather often occurs in the Yangtze River basins. This is the so-called “plum rains” season.

Plum rains, often occurring during June and July, refer to the long period of continuous rainy or cloudy weather accompanied by frequent and large amounts of rainfall. June and July are also time for plums to become ripe, so it is called plum rains. Due to high temperatures and a lot of rainfall, which leads to high humidity, it is also called mold rains.

Normally, plum rains last for 20 to 30 days, from mid-June to early July. The amount of rainfall is 200 to 300 mm, which is 20% to 30% of the local total rainfall. The beginning date of plum rains can differ by 40 days and the end of it can differ by 45 days. Exceptions like no plum rains can also occur. But that is really rare.

Plum rains is a good period for growing rice, vegetables and fruits. People in southern China have known about plum rains. They can take advantage of the climate resources and arrange farming activities accordingly.

Many people complain about the dampness caused by too much rainfall during the plum rains season, even as people acknowledge that plentiful rainfall is a necessary condition for human survival. If there is not enough rainfall, there will be no rice fields, verdant trees and branching streams.

But extremely unusual plum rains can also cause disasters such as floods or continuous droughts. The floods in 1931, 1954 and 1991 in the Huai river basin were all caused by extremely large amounts of rainfall during the plum rain season. The floods brought great damage to people’s property and safety. While, on the opposite side, if the rainfall during plum rain season is too little, droughts can happen.

As meteorological observation technologies continue to develop, people know more and more about plum rains. In order to ensure the safety of people and their properties, measures such as clearing dead furrows and dredging sewers should be taken before the arrival of plum rains. In years with late or no plum rains, people should prepare for droughts to ensure a stable and high agricultural yield.