Great Heat, or Dashu in Chinese, is the 12th solar term in the traditional 24-solar-term cycle, typically beginning around July 22nd and ending around August 6th. It occurs when the Sun reaches the celestial longitude of 120°. The term signifies that the weather has reached its most extreme point of heat, marking the peak of the "dog days" (sanfu) and the zenith of summer's scorching intensity. It represents the culmination of the year's thermal energy, after which the heat will gradually begin to wane.
In terms of agricultural phenology, Great Heat is a period of rapid maturation for many crops, as well as a season of frequent typhoons, torrential rains, and droughts. In southern China, the double-cropping rice harvest and planting season is in full swing, a period farmers call "grabbing the harvest in the heat" (qiangshou qiangzhong). The farming proverb, "During Great Heat, be busy with both harvest and planting, and do not miss the farming season," underscores the critical importance of this time for agricultural production, irrigation, and disaster prevention.
Historically, Great Heat has nurtured a variety of customs centered around cooling off, nourishing the body, and enduring the extreme heat. The folk tradition of "drinking fu tea" involved brewing herbal teas with medicinal properties to dispel dampness and relieve internal heat. In many regions, the custom of "eating grass jelly" (xiancao) was popular, as this dark, jelly-like dessert was believed to cool the body and provide relief from the sweltering heat. Additional customs include eating pineapples in Taiwan, where the fruit's pronunciation suggests "prosperity," and consuming lychees and rice porridge in Fujian and Guangdong to replenish energy and moisture. In some areas, people also practice "sunning ginger" (fushuojiang) on dog days, as ginger is thought to dispel cold and improve circulation during the hottest season. These traditions reflect a deep understanding of nature's rhythm and the wisdom of maintaining health and harmony amidst the peak of summer's relentless heat.
By Yuan Ruichen/ Zhang Yishuo
