Spring
Grain Rain
Apr 20–May 4
Grain Rain (Guyu) is the sixth solar term of the twenty‑four solar terms, and the final chapter of spring. It marks the arrival of the sun at the celestial longitude of 30°, and takes its name from the saying “rain brings up the growth of hundreds of grains”. This article explains in detail its climatic characteristics (frequent rainfall in the south, the end of frost in the north), the phenological phenomena of its three pentads (duckweed begins to grow, turtle doves call, hoopoes descend on mulberry trees), its flower trade winds (peony, brambles, chinaberry), and folk customs such as picking Guyu tea, “walking through Guyu” (strolling in the fields to pray for health), sacrificing to the sea, and eating spring vegetables. Grain Rain is an important solar term that reflects precipitation and its role in farming.
Grain Rain (Guyu) is the sixth of the twenty-four solar terms and the final solar term of spring. It occurs when the Big Dipper points to the terrestrial branch chen and the sun reaches the ecliptic longitude of 30°, typically falling on April 19–21 in the Gregorian calendar. The name “Grain Rain” derives from the saying “rain gives birth to a hundred grains.” At this time, precipitation markedly increases. The rice seedlings have just been transplanted in the fields and the crops are newly sown, requiring the nourishment of rain most urgently. With sufficient and timely rainfall, the cereal crops can thrive. Like the solar terms Rain Water, Lesser Fullness, Lesser Snow, and Greater Snow, Grain Rain reflects the phenomenon of precipitation and is a reflection of ancient agricultural culture's attention to seasonal rhythms.
During the Grain Rain period, rainfall often becomes markedly more frequent in the southern regions of China, and especially in South China, where the convergence of cold and warm, moist air masses tends to produce extended periods of rainy weather. The Qinling Mountains–Huaihe River line serves as a transitional zone between the spring rains of the south and the spring drought area of the north. Northward from this line, the spring rainfall diminishes sharply. In the northern regions, Grain Rain symbolizes the “final frost.”
Gentle, persistent spring rain is the defining characteristic of Grain Rain. The name of this solar term originates from the ancient observation that “rain gives birth to a hundred grains,” reflecting the agroclimatic significance of the season. In certain ancient Chinese texts, Grain Rain is divided into three pentads: “In the first pentad, duckweed begins to grow; in the second pentad, the singing cuckoo flutters its wings; in the third pentad, the hoopoe descends upon the mulberry tree.” The flower-wind sequence for Grain Rain is: first, the peony; second, the roseleaf raspberry (tu mi); third, the chinaberry flower. Folk customs during the Grain Rain period include picking Grain Rain tea, taking a stroll through the Grain Rain (zou guyu), offering sacrifices to the sea, eating spring delicacies (chi chun), and enjoying the blossoms.
