What does the heat represent?

Long summer is the 14th solar term among the 24 solar terms, and autumn is the second solar term. Dou Zhiwu (Southwest); The solar meridian reaches150; August 22-24 of the Gregorian calendar every year. Summer has arrived, which is the "last summer" in the "three summers" of hot and hot weather, which means that the hot and difficult weather is coming to an end.

Entering summer is a solar term that reflects the change of temperature. The original meaning of "going out" means "stopping" and "staying". "Shuo Wen Jie Zi" said: "Stop. The Ministry said that the extremely hot weather came to an end and the summer heat began to fade. Both "three summers" and "three volts" represent hot and humid weather, and the curves on the time axis and the temperature axis are basically the same: summer is coming, summer is coming; When the sky falls, summer is over.

There are "three summers" in the 24 solar terms, namely, little summer, big summer and long summer, followed by early summer, heatstroke and late summer. There is also a "beginning of autumn" solar term in the middle of the "Three Summers". After beginning of autumn, it is summer, and the heat lasts for a long time. Long-term intense heat is beneficial to the growth and yield of crops. The ancients called the period from beginning of autumn to the autumnal equinox "long summer".

The dog days include four solar terms: Slight Summer, Great Summer, beginning of autumn and Summer. By the time of the heat, the dog days have passed or ended. The summer heat subsides slowly, and it doesn't get cold as soon as it drops. Although the summer solar term is still hot, the temperature has generally begun to show a downward trend.