How many days is one volt?

The first and last days are ten days, sometimes ten days and sometimes twenty days in the middle. If beginning of autumn stays in the midriff for ten days after the fourth Geng Day of the summer solstice, and stays in the midriff for twenty days after the fifth Geng Day, in short, the last beginning of autumn must be behind beginning of autumn. So the dog days are sometimes thirty days, and sometimes forty days. The solar calendar from mid-July to late August is the hottest time in summer in China, and the middle volt is the hottest among the three volts.

Three volts is the general name of the initial, middle and final volts, and it is the hottest period in a year. V means being forced to hide underground. The dog days appear in the Gregorian calendar from mid-July to mid-August every year, and its climatic characteristics are high temperature, low pressure, high humidity and low wind speed. The so-called heat is in volts, which can be divided into initial, middle and final volts, and its date is determined by the date when the solar terms cooperate with the main branch year.

The hottest weather in dog days

After lodging, the humidity of the ground becomes higher, and the heat absorbed by the ground is more and more day by day, and the heat emitted is less and less day by day, so the heat accumulated on the ground is hotter and hotter every day. When entering the alto, the heat accumulated on the ground reaches the highest value, and the weather is the hottest. There is a saying that it is "cold in March, hot in dog days", which means that the hottest day of the year belongs to dog days. Judging from the accumulation of solar energy, the dog days are the hottest.

In summer, there is much rain and high air humidity, and the heat capacity of water is much larger than that of dry air, which is also an important reason for the sultry weather in dog days. In July and August, the subtropical high intensified. Under the control of the subtropical high, the descending airflow inside the high made the weather clear and partly cloudy, which was beneficial to sunshine, the ground radiation warmed up and the weather became hotter.