It is said that if winter comes, can spring be far behind? Spring has arrived for many days, and summer will come soon. It's the hottest time of the year. So, when is the first ebb in 2019? Which one is the hottest?
The Yangtze River Basin should be the hottest in the middle of the Yangtze River Basin, and the northern part tends to be hotter in the early part. But there are still some differences. First of all, the time of three volts is different every year, and the length can be 30 days or 40 days. The reason for 40 days is that there are 20 days in the middle of the year. This long version has more three volts, about 2 / 3 or even 70% of the year. This is related to the three volt algorithm.
The third Geng day after the summer solstice enters the first ambush. Generally, the summer solstice is between June 21 and 22. If it is very soon the Geng day (the ancients used the heavenly stems and earth branches to record the dates, the heavenly stems were 10, and the cycle lasted for 10 days). If it was earlier, it would enter the first ambush on July 12. If it happened to be the Geng day just before the summer solstice, it would be late, probably to July 20. Generally, autumn begins on August 7, and the first day after the beginning of autumn is the beginning of the end. If there is a long distance between the first and the last, then the middle is 20 days. For example, this year, because August 6 is the day of Geng and the seventh is the beginning of autumn, so August 16 is the last day. From this point of view, the middle of July generally enters the early stage, the late July to the first ten days of August is generally in the middle, and the middle of August sometimes contains a period of late ten days, which is in the last period.
Generally, in China, the hottest period is between July 6 and August 7, especially in the Yangtze River Basin. In this period, it is mainly in the middle. The hot period in the north is generally earlier than that in the south, and sometimes it is the hottest in the first and middle of July, that is to say, it is inclined to the early incubation period. At the end of the day, in addition to Chongqing sometimes there are some extreme high temperature, most areas are not so hot.
The key to when it's hottest is to look at the sun's heating, one is the angle of incidence of the sun, the other is the covering of clouds. Usually around the summer solstice, the sun is directly in the northern hemisphere, so this is the time when the light heats up the most. However, there is a lag due to the ground heating and re conducting the atmosphere, so it will reach the maximum temperature in July to August. At this time, it depends on the cloud cover. Generally, the rainy season in the northeast of North China is from late July to early August, with more clouds, which is not conducive to solar heating. Therefore, it is often hotter in mid July, while from late July to early August, the subtropical high often controls the Yangtze River Basin, resulting in sunny and cloudless weather, which is conducive to temperature rise and high temperature.