Why is it hot in dog days?

The dog days are the hottest time of the year. First of all, it is related to the angle of the sun. Every summer, the sun shines directly on the northern hemisphere, which gets the most sunshine. The sun's light and heat are absorbed, scattered and reflected by the atmosphere, reaching the ground more. Secondly, in summer, the days are longer than the nights, and the sunshine time is longer. The heat absorbed by the surface is far greater than the expenditure, which makes the heat accumulated on the surface increase day by day and the temperature continues to rise. In dog days, the accumulation of surface heat reaches its peak. At the same time, under the control of the subtropical high, the descending airflow inside the high makes the weather clear and cloudy, and the ground radiation heats up. Secondly, the summer solstice is the longest day in a year, and the sunshine is close to direct sunlight. However, due to the low surface humidity during the summer solstice, most of the heat absorbed by the ground will be emitted at night, so it is not the hottest. After entering the dog days, the humidity of the ground becomes larger, and the heat absorbed every day is more, but the heat emitted is less, and the heat on the ground accumulates, so it gets hotter every day. When entering the dog days, the accumulated heat on the ground reaches its peak, and the weather is the hottest.

In addition, there is much rain in summer, the air humidity is high, and the heat capacity of water is much greater than that of dry air, which is also an important reason for the sultry weather. In July and August, the subtropical high intensified. Under the control of subtropical high, the descending airflow inside the high makes the weather clear and partly cloudy, which is beneficial to sunshine and ground radiation warming.

Experts remind that people should pay more attention to eating some light food for heatstroke prevention and cooling, such as mung bean soup, winter melon soup, green tea and watermelon. In addition, when using air conditioning as a summer tool, we should pay attention to the correct use, don't use the air conditioner continuously for too long, don't sleep with the air conditioner on all night, and don't adjust the temperature too low, otherwise it will easily lead to "air conditioning disease", which is more painful than "heat". In addition, in order to prevent the summer heat from entering the heart, it will lead to excessive internal heat. In the "dog days", we should also guard against anxiety and impatience, and always maintain the tolerance of "not being angry when things happen".