What does "dog days" mean?

The dog days are the hottest, humid and sultry days in a year between the hot summer and the hot summer.

The so-called "dog days" refers to the "dog days" of the lunar calendar, which is the hottest period of the year. It can be understood as "squatting" means that the weather is too hot to move. But the dog days are called "dog days" because there are also many cold factors. The dog days are the hottest thirty or forty days in a year in the Central Plains. The dog days are calculated according to the lunar calendar, between the middle and late July and the early August of the solar calendar.

After lodging, the surface humidity increases, and the heat absorbed every day is more, but the heat emitted is less, and the heat on the surface is accumulated. So it gets hotter every day, and when it enters the dog days, the accumulated heat on the ground reaches its peak and the weather is the hottest. The subtropical high intensified in July and August. Under the control of the subtropical high, the descending airflow inside the high makes the weather clear and cloudy, which is beneficial to the sunshine, the ground radiation heats up and the weather is hotter.