Major Heat

Major heat arrives. The sun scorches the earth, and all living things seek shelter from the blaze.

Major Heat is the year's furnace. The air is thick, the ground is hard, and every living thing conserves its energy. But the calendar places this term at the end of summer, not the beginning. The worst heat comes just before the turn toward autumn. There is a pattern here: the most intense moment of any season is also the signal that it is almost over. Endurance is not about fighting the heat. It is about knowing that the heat has a limit.

Dashu, the twelfth solar term, falls around July 22 to 24 when the sun reaches 120° of celestial longitude. It is the last term of summer and typically the hottest period of the year across China. Its name is unambiguous: 大 (dà) means "major" and 暑 (shǔ) means "heat." This is the peak of summer's intensity. Three pentads describe rotting grass transforming into fireflies, the soil growing damp and hot, and heavy rains arriving. The firefly observation is particularly poetic — even in decay, the summer produces light. These heavy rains of Dashu are critical for the rice crop but also bring the risk of flooding, a constant tension in Chinese agricultural life. In traditional Chinese dietary practice, Dashu is associated with consuming cooling foods — mung bean soup, bitter melon, watermelon — to counteract the external heat. These are cultural practices, not medical recommendations. This term's deeper meaning is about the relationship between extremes and transitions: the hottest day contains within it the promise of autumn. What feels unbearable is also temporary. The calendar's wisdom is not to escape the heat but to recognize its place in a larger cycle.

“Hottest period” is a broad regional tendency, especially in East Asian continental climates, rather than a global guarantee. Cooling foods are named as traditional dietary customs only; they make no therapeutic promise. The astronomical marker helps explain why a peak can coexist with the first signs of decline.