When the sun's ecliptic longitude reaches 285 degrees, the Xiaohan solar term begins. Han means cold, and small cold indicates the degree of coldness.
In southern China, the winter is significantly warm, in the middle of winter in January, frost and snow are intertwined, and there are often freezing, and the lowest temperature is about minus 10. However, the minimum temperature in northern South China is rarely lower than minus 5, and low temperatures below 0 in southern China are even rarer.
The coldest area in China in midwinter is the northern part of Heilongjiang, where the lowest temperature can reach around minus 40.
The low-altitude river valleys are the warmest in the middle of winter in most parts of southern China, with an average temperature of around 12 in January, with only a few years when low temperatures below 0 may occur. In addition, the temperature inversion effect is very significant, so tropical fruits such as bananas and mangoes can grow well.
During the Xiaohan solar term, the East Asian trough developed the most powerful and stable, the Mongolian cold high and the Aleutian low also reached the strongest and stable, and the westerly trough ridge reached the maximum and cooperated with the strongest westerly intensity. The cooling process of cold air in the small cold season is frequent, but not many of them meet the cold wave standard.
Xiaohan solar term activity.
1.Ninety-nine songs.
In order to survive the cold winter, there used to be a custom of "counting ninety-nine" in the north. In the eighty-one days from 19 to 99, each nine has differences with each other, and the ancients compiled an easy-to-understand ninety-nine song based on the accumulation of long-term experience, such as "19 can't call each other out, 29 invites each other to walk on the ice, 39 freezes the cat to death, 49 freezes the dog to death, 59 looks up at the willow, 69 poor children fight, 79 rivers open, eight." Nine swallows come, and ninety-nine ploughs and rakes come out together. ”
2.Eat vegetable rice.
In the Jiangnan area, when you arrive in Xiaohan, you will generally cook vegetables and rice to eat, the content of the vegetables and rice is not the same, there are short-legged yellow vegetables and salted pork slices, sausage slices or duck dices, and then chop some ginger grains and glutinous rice to cook together, it is very fragrant and delicious. Among them, bantam yellow, sausage, and duck are all famous specialties of Nanjing, which can be described as the real "Nanjing cuisine rice", and even comparable to Laba porridge. According to the tradition of Guangzhou, Xiaohan eats glutinous rice in the morning, in order to avoid being too glutinous, it is generally 60% glutinous rice and 40% fragrant rice, chop the bacon and sausage, fry it, fry the peanuts, add some chopped green onions, and mix it in the rice to eat.
The origin of the Xiaohan solar term.
The Xiaohan solar term is the 23rd of the 24 solar terms. During the light cold, the sun travels to 285° ecliptic longitude. After a small cold, China's climate began to enter the coldest period of the year. As the saying goes, air conditioning accumulates for a long time and is cold. At this time, the weather is cold, and the big cold has not yet reached the extreme, so it is called Xiaohan.
Climatic observation data show that the temperature in most parts of China during the solar term from "small cold" to "big cold" is the lowest in the whole year.
Ancient folk proverbs such as "walking on the ice" and "small cold, big cold and freezing together" and "walking on the street, losing money" are all to describe the cold of this season. Due to the very low temperature, wheat, fruit trees, melons and vegetables, livestock and poultry are susceptible to freezing cold.
Why is it called a small cold and not a big cold?This is because the solar terms originated in the Yellow River Valley. In the "Seventy-two Candidate Explanations of the Lunar Order", it is said that "the cold at the beginning of the month is still small......The moon and a half are bigger", that is, in the Yellow River Valley, the big cold was colder than the small cold at that time. And because Xiao Han is still in the last few days of the "Twenty-Nineth", Xiao Han only entered the "Thirty-Nine" a few days later, and the small cold in winter is exactly the same as the summer heat.