How many days does the solstice enter the dog days after summer?

1, the third day after long summer was ambushed.

2. The first day (10), the middle day (10 ~ 20) and the last day (after beginning of autumn 10) are the hottest days of the year.

3. "Three volts" refers to the first, middle and last three volts, which is about mid-July to mid-August. After the summer solstice, although the days are getting shorter and the nights are getting longer, the days are longer than the nights in a day. Every day, the ground absorbs more heat than it emits, and the temperature near the ground is getting higher every 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. After that, the heat absorbed by the ground began to be less than the heat emitted by the ground, and the temperature gradually decreased. Therefore, the hottest time of the year generally appears in the "dog days" from the summer solstice.

Extended data:

Summer solstice was also called "Summer Festival" and "Summer solstice Festival" in ancient times. The ancients said: "The days are long, the shadows are short and extremely extreme, so it is called the summer solstice." When the sun moves to the longitude of the Yellow River at 90 degrees, it is the intersection of the summer solstice, usually on June 2 1 ~ 22 of the Gregorian calendar.

On the solstice of summer, the sun shines directly on the Tropic of Cancer. At this time, the daytime in all parts of the northern hemisphere reaches the longest in the whole year, and the higher the latitude, the longer the daytime. For the Tropic of Cancer and its northern area, the summer solstice is also the highest day of the year at noon.

The summer solstice is not only one of the 24 solar terms, but also a festival in the ancient folk "four seasons and eight festivals". Since ancient times, there has been a custom of offering sacrifices to gods and ancestors to the Japanese. "Heaven and earth are the foundation of life; Ancestors are the foundation of class. " Heaven and earth are the foundation of life, ancestors are the foundation of life, and ancestor worship is the custom of inheriting filial piety. In addition, there are folk customs such as "avoiding summer and hiding" and "clearing the field" from summer to Japanese.