Lesser Fullness

Lesser Fullness (Xiaoman) is the eighth solar term of the twenty-four solar terms and the second solar term of summer. “Xiaoman” means that all things have reached a state of modest fullness at this point. In the north, summer-ripening crops such as wheat are growing vigorously, and the grains are gradually swelling with milky substance but have not yet fully matured — hence the name “Lesser Fullness.”

Xiaoman occurs when the Big Dipper points to the celestial stem jia and the sun reaches the ecliptic longitude of 60°, typically falling on May 20–22 in the Gregorian calendar. The name Xiaoman carries two layers of meaning. First, it relates to climate and precipitation. During the Xiaoman period, rainstorms in the southern regions become more frequent, and precipitation is abundant; as the folk saying goes, “Lesser fullness, lesser fullness, rivers and streams gradually fill.” Here, the “fullness” refers to the abundance of rainfall. Second, it relates to agriculture, specifically wheat. In the northern regions, rainfall during Xiaoman is scarce or even absent; here, “fullness” does not refer to precipitation but rather to the degree of plumpness of the wheat grains.

During the Xiaoman solar term, China's southern regions generally receive frequent and heavy rainfall. The warm, moist air currents from the ocean are active and converge with cold air masses moving south from the north. In South China, this often results in sustained, large-scale heavy precipitation, leading to torrential rain or exceptionally heavy rainstorms. In the Jiangnan (south-of-the-Yangtze) region, rivers and lakes often fill to the brim. If rainfall during this phase is relatively scarce, it may indicate that the Pacific subtropical high-pressure system is weak and its position is too far south, signaling the approach of the plum rain (Meiyu) season. In the north, rainfall during Xiaoman is minimal or absent, while temperatures rise rapidly, further narrowing the temperature difference with the south.

The “Twenty-Four Solar Terms” are a product of ancient Chinese agrarian civilization. They are not only a seasonal system guiding agricultural production but also a folkloric system rich in cultural phenomena. The folk customs of Xiaoman were shaped by the characteristics of agricultural society, and the main customs include: “offering sacrifices to the cart god,” “operating the three wheels (the water wheel, oil press, and silk reel),” “water grabbing,” “the silkworm prayer festival,” and “eating wild greens.”