When is the hottest time in summer?

The hottest time in summer is the "dog days". "Three Volts" refers to the first, middle and last days, which is from mid-July to mid-August every year. After the summer solstice, although the days are getting shorter and the nights are getting longer, the days are still longer than the nights. The ground still absorbs more heat than it emit, and the temperature near the ground is getting higher day by day. During the "three volts" period, the heat absorbed by the ground is almost less than the heat emitted, and the weather is the hottest. Later, the heat absorbed by the ground begins to be less than the heat emitted by the ground, and the temperature slowly drops. Therefore, the hottest time of the year usually occurs during the "three days" of the summer solstice.

As for the hottest solar term, the Great Heat solar term is the hottest solar term of the year. The reason why the "Great Heat" period is extremely hot is because since the beginning of summer, the ground has absorbed more heat from the sun during the day than is emitted at night. The heat has continued to accumulate. During the Great Heat period, the accumulated heat has reached its peak. So Great Summer is the hottest. Toufu and Erfu span the Great Heat and are the hottest days of the year. Although it is the beginning of autumn during the dog days, the weather is still hot, so it is also known as the "autumn tiger".

Because the first, second and third volt days are very hot, so it is called "hot in the third volt"