Grain Rain is the sixth solar term of the twenty-four solar terms and the last one in spring. When the Big Dipper points to the east, the sun's ecliptic longitude reaches 30°, marking the transition from April 19 to 21 in the Gregorian calendar each year. The name "Grain Rain" signifies "rain nourishing all crops." During this period, rainfall significantly increases, as newly transplanted seedlings and newly sown crops most urgently need moisture. With adequate and timely precipitation, grain crops can thrive. Like Rain, Grain Full, Light Snow, and Major Snow, Grain Rain is a solar term that reflects precipitation phenomena, embodying the ancient agricultural culture's adaptation to seasonal changes.
During the Grain Rain season, in southern China, there is often a noticeable increase in rainfall, especially in southern China. Once cold air meets warm and humid air, it often leads to prolonged periods of rainy weather. The Qinling Huaihe River is a transitional area between the spring rain in the south and the spring drought in the north. From the vicinity of the Qinling Huaihe River to the north, the spring rain decreases sharply. In northern regions, Grain Rain is a symbol of "final frost".
Due to the increased rainfall after the Grain Rain solar term, the humidity in the air gradually increases, and attention should be paid to preventing the invasion and harm of "dampness evil" to the body. Folk customs include picking Guyu tea, walking through Guyu, eating spring, and admiring flowers during the Guyu solar term.
