Introduction of 24 solar terms and summer heat.

1, Xiaoxia is the 11th solar term among the 24 solar terms of the lunar calendar and the fifth solar term in summer, which marks the official start of the last month of summer. On July 7th or 8th every year, when the sun reaches longitude 105, it is considered as a slight summer heat. Summer heat means heat, and a little summer heat means slight heat, which means the weather is getting hot, but it is not the hottest yet. This climate is basically the same in most parts of China.

2. The average temperature in the south of China is around 26℃ in summer, which is already midsummer. All localities have also entered the season with the most thunderstorms, often accompanied by strong winds, heavy rains and sometimes hail. Most areas in the south are flooded in the east and west, so drought and flood control measures must be taken as soon as possible to minimize the harm. In most agricultural areas of China, crops in China have entered a vigorous growth stage after the harvest in May of the lunar calendar and before and after the light summer, except for winter and spring wheat harvested in Northeast and Northwest China. Farming is mainly a variety of field management work, and topdressing and pest control should be carried out according to the growth.

There was a custom of "eating new things" in the past summer. "Fresh food" means grinding new dozen rice and wheat into powder, making all kinds of cakes and noodles, which are shared by neighbors and villagers to express their desire for a bumper harvest. At the same time, these new goods should also prepare a sacrifice for their ancestors, and please bless the good weather.

4. After the slight summer heat, the head heat wave of "dog days" hit. Northerners are used to drinking porridge in summer, mainly for clearing away heat and heatstroke and regulating the stomach. Fried mung bean sprouts have become the first choice for side dishes. There is also the custom of "eating lotus root in summer" in many places, because lotus root has an appetizing effect and is suitable for eating in summer. Su Dongpo, a poet, called watermelon "ice slurry fairy liquid", which can clear the heart after eating it. Although light summer is not the hottest season in a year, it is followed by the hottest summer in a year. There is a folk saying that "it is hot in summer and hot in summer, and the weather will become more and more sultry and humid."

5. Historical depth: "Twenty-four solar terms": "June is hot, and the summer heat is divided into different sizes. Small at the beginning of the month, big in the month, and the heat is still small today. " Summer is hot. The ancients thought that the summer heat period was not the hottest time of the year, so it was called summer heat. There is also a solar term ballad: "Little summer is not hot, big summer is three days." It is pointed out that the hottest period of the year has arrived, but it has not reached the extreme hot level. As the saying goes, "the heat is at three volts." The dog days in China generally occur on the 28th day from summer to the future, which is the so-called "summer solstice is the first night". Since then, crops all over the country have entered a vigorous growth period, and field management needs to be strengthened.