Why is beginning of autumn called beginning of autumn?

In ancient times, autumn was called early autumn, early autumn, early autumn, early autumn, new autumn and late autumn in the lunar calendar, autumn in August, mid-autumn, mid-autumn and guiqiu, and autumn in September.

In China, traditionally, "beginning of autumn" in the 24 solar terms is taken as the starting point of autumn. Entering autumn means that rainfall and humidity tend to decrease or decrease. In nature, the qi of Yin and Yang began to change, the yang gradually declined, the yin gradually emerged, the climate changed from hot to cold, and everything was born with cold and gradually declined.

According to modern meteorology, the autumn in the north temperate zone is from August 23rd (summer) to165438+1October 22nd (light snow). Autumn in the south temperate zone is from February 19 (rain in the northern hemisphere) to May 2 1 (xiaoman in the northern hemisphere).

Autumn temperature:

Beginning of autumn doesn't mean that the hot summer will be over. beginning of autumn is still in the heat period, and the heat will not come out until the second solar term in autumn, and the weather is still very hot in early autumn.

The so-called "heat is in three volts", according to the calculation method of "three volts", beginning of autumn is often still in the "three volts" period until the summer heat, so the weather is still very hot in early autumn, and it will generally cool after the Millennium solar terms. The watershed of summer heat is in autumn, not at the turn of summer and autumn. The climate in autumn is divided into two stages, the early autumn is sultry, and the climate tends to be dry and cool after the Mid-Autumn Festival.

The autumn standard of average temperature adopted in meteorology is that after the intense heat, the five-day average temperature will be kept below 22℃, that is, it will enter autumn, and when it is lower than 10℃, it will end in autumn and enter winter.