The dog days are the hottest time of the year. Which one is the hottest? Why is it so hot? How is the date of Sanfu determined? Let's get to know with Xiaobian.
The reasons for the formation of three dog days
After falling into the ground, the surface humidity becomes larger, more heat is absorbed every day, less heat is emitted, and the heat of the surface layer accumulates, so it gets hotter day by day, entering into the third volt, the accumulated heat of the ground area reaches the highest peak, and the weather is the hottest.
In addition, there is more rain in summer, and the air humidity is large. The heat capacity of water is much larger than that of dry air, which is also an important reason for the sultry weather. In July and August, the subtropical high was strengthened. Under the control of the subtropical high, the downdraft inside the high pressure made the weather clear and cloudless, which was conducive to the sunshine, the ground radiation increased temperature, and the weather was even hotter.
What's the hottest day
The hottest stage of three dog days: Zhongfu
1. When it comes to which one of the three volt days is the hottest, we need to mention the folk saying "cold in Sanjiu, hot in Zhongfu", which means that the hottest day of the year belongs to the "three volt", and the "three volt" is the hottest. After the end of the day, the weather began to cool.
2. First of all, as the surface humidity increases after the fall, the heat absorbed by the ground every day is more, the heat emitted is less, and the heat of the surface layer accumulates, so it gets hotter day by day. Entering the middle voltage, the heat accumulated on the ground reaches the highest value, and the weather is the hottest.
3. In addition, there is more rain in summer, and the air humidity is large. The heat capacity of water is much larger than that of dry air, which is also an important reason for the sultry weather in three rainy days.
4. In July and August, the subtropical high pressure was strengthened. Under the control of the subtropical high, the downdraft inside the high pressure made the weather clear and cloudless, which was conducive to the sunshine, the ground radiation increased temperature, and the weather was even hotter.
5. After entering the final days, the weather is gradually cool. It's cooler in the morning and evening. It's still hot at noon. Each area will be different. Because the last fall is after the beginning of autumn, even the so-called "autumn tiger" is hot in the daytime and cool in the morning and evening.
How to determine the date of Sanfu
First fall, according to China's calendar law, this is the beginning of a real summer day. The people often say: heat in three volts, cold in three nineties. The three dog days are the season with the highest temperature and humidity in a year, which are divided into the first, the middle and the last, in which the first and the last are fixed for 10 days, some are 10 days, some are 20 days.
At the beginning of the incubation period, it is called in or in, and at the end of the incubation period, it is called out. The number of medium voltage days depends on the time of lodging. Generally, the number of days of lodging before July 28 is 20 days, the number of days of lodging on July 29 is 10 days.