What are the two solar terms in dog days?

The dog days are generally between the heat and the summer solar terms.

The dog days, which appear between the light summer heat and the hot summer heat, are the time when the temperature is the highest and it is humid and sultry in a year. Three volts can be divided into initial volts, intermediate volts and final volts, and their dates are determined by the coordination of solar terms and solar terms in the dry branch calendar. After "entering the volt", many places in the country will enter the continuous high temperature mode.

The traditional almanac stipulates that "counting from the third Geng day in summer", that is to say, "counting down from the summer day until the third Geng day" is about to begin to dormant. The "Geng Day" here refers to the days prefixed with "Geng" in the ancient "Ganzhi Jiri Law". "crouching" means being forced to hide underground; This also means that it is too hot to move. ?

The length of dog days mainly lies in the difference between middle and next days. Because the third Geng day (the first autumn) after the summer solstice solar term occurs at different times every year, the number of days in the middle autumn is also different. The incubation time is long or short, which may be 10 day or 20 days. So there are two situations: some years are 30 days in dog days, and some years are 40 days.

The dog days are the hottest, wettest and sultry time of the year. The reason why the air humidity is high in dog days is that the southeast wind blows in dog days, while the southeast is the ocean and the air is humid. The humidity of the sea breeze leads to the high humidity in dog days. In dog days, "high temperature and high humidity" is the climate characteristic of southern China. The inland areas in the north are far from the ocean, and the climate is characterized by "high temperature and dryness".