There are 24 solar terms in a year, in order: Winter Solstice, Minor Cold, Major Cold, Beginning of Spring, Rain, Waking of Insects, Vernal Equinox, Qingming, Grain Rain, Beginning of Summer, Xiaoman, Ear Grain, Summer Solstice, Minor Heat, and Major Heat , the beginning of autumn, the end of summer, white dew, autumnal equinox, cold dew, frost, beginning of winter, light snow, and heavy snow.

Introduction to solar terms

The beginning of spring: Dou refers to the northeast. The solar longitude is 315 degrees. It is the first solar term among the twenty-four solar terms. The meaning is that spring has begun, "when the sun rises and hibernates, everything becomes spring." After the beginning of spring, everything comes to life and becomes full of vitality, and the four seasons of the year begin.

Rain: Douzhiren. The solar longitude is 330°. At this time, the spring breeze blows everywhere, the ice and snow melt, the air is moist, and there is more rain, so it is called rain. People often say: "The beginning of spring is getting warmer, and the rain is busy bringing fertilizer."

Jingzhe: Fighting fingers. The solar longitude is 345°. This solar term means that the weather will get warmer after the "beginning of spring", the spring thunder will begin to ring, and various hibernating animals dormant in the soil will wake up and start to move, so it is called Jingzhe. During this period, the eggs of overwintering insects will also begin to hatch. The spring plowing season has entered in some areas of our country. The proverb goes: "After the Waking of Insects, it is warm and gentle, and the old horns of the toad sing folk songs." "The Waking of Insects plows the soil, and the spring equinox clears the earth." "The Waking of Insects does not arrive before thunder sounds, and the heavy rain is like a dragon."

Spring Equinox : Douzhiren. The solar longitude is 0°. On the vernal equinox the sun is above the equator. This is the midpoint of the 90 days in spring. On this day, day and night are equal in the northern and southern hemispheres, so it is called the vernal equinox. After this day, the direct position of the sun moves northward, making the days longer and nights shorter in the northern hemisphere. So the Vernal Equinox is the beginning of spring in the Northern Hemisphere. Overwintering crops in most areas of my country have entered the spring growth stage. Farmers' proverbs from various places include: "The vernal equinox is ahead, and rice and money are fighting" (Guangdong), "The spring equinox is full of rain, and the summer equinox is full of fire" (Sichuan), "Every family is busy when it rains on the spring equinox, so plant melons and beans first and then transplant the rice seedlings" (Hubei) ), "Grow vegetables on the spring equinox and pick melons in the hot summer" (Hunan), "Grow hemp and beans on the spring equinox, and plant wheat and garlic on the autumn equinox" (Anhui).

Qingming: Dou Zhiding. The solar longitude is 15°. At this time, the climate is refreshing and warm, vegetation begins to sprout new branches and buds, everything begins to grow, and farmers are busy with spring plowing and spring planting. In the past, on the Tomb Sweeping Day, some families would put willow sticks at their doorsteps, go outing in the countryside, and visit graves. This is an ancient custom.

Gu Yu: Dou Zhigui. The solar longitude is 30°. It means rain produces grains. Since rainwater moistens the earth and grains grow, Grain Rain means "rain produces grains." As the proverb goes, "Before and after Grain Rain, you plant melons and beans."

Lixia: Dou refers to the southeast. The solar longitude is 45°. It is the beginning of summer. From then on, summer comes and everything is prosperous. It is customary to regard the Beginning of Summer as the most important solar term when the temperature rises significantly, the heat is approaching, thunderstorms increase, and crops enter the peak season.

Xiao Man: fighting nails. The solar longitude is 60°. Starting from Xiaoman, summer crops such as barley and winter wheat have already produced fruits and have full grains, but are not yet mature, so they are called Xiaoman.

Manzhong: The Big Dipper is pointing towards you. The solar longitude is 75°. At this time, it is most suitable to sow cereal crops with awns, such as late grain, millet, millet, etc. If you plant awns and crops after this time, they will not mature well. At the same time, "awn" refers to crops with awns such as wheat, barley, etc., and "kind" refers to seeds. Ear seeds indicate that crops with awns such as wheat are mature. Around the time of Ear Grain, in the middle and lower reaches of the Yangtze River in central my country, rainfall increased and temperatures rose, entering the plum rain season with continuous rain. The air was very humid, the weather was extremely hot and muggy, and various utensils and clothing were prone to mold. Therefore, in the middle and lower reaches of the Yangtze River in my country, Also called "mold rain".

Summer Solstice: The Big Dipper points to B. The solar longitude is 90°. When the sun is at the "summer solstice" point of 90° ecliptic longitude, the sun shines almost directly over the Tropic of Cancer, and the sun is highest at noon in the Northern Hemisphere. This day is the day with the longest day and the shortest night in the Northern Hemisphere. From this day on, the hot season begins, when all things in the world grow most vigorously. Therefore, in ancient times, this day was called the northern solstice, which means the day when the sun reaches its northernmost point. After the summer solstice, the sun gradually moves south, the days in the northern hemisphere are getting shorter and the nights are getting longer.

Small Heat: Fighting means pungent. The solar longitude is 105°.

The weather is already very hot, but it is not yet the hottest period, so it is called Xiaoshu. At this time, it was around the time of Chufu.

Great Heat: Dou Zhi C. The ecliptic longitude of the sun is 120°. Great Heat is the hottest solar term of the year. Around the time of Qin Erfu, high temperatures of 40℃ often occur in many places in the Yangtze River Basin. It is necessary to do a good job in preventing heatstroke and cooling down. There is a lot of rain during this solar term. As the proverb goes, "Small heat or severe heat will drown mice." Pay attention to flood prevention and waterlogging.

The Beginning of Autumn: The Beidou points to the southwest. The solar longitude is 135°. From this day, autumn begins, the air is crisp, the moon is bright and the wind is clear. After that, the temperature gradually dropped from the hottest.

End of heat: Douzhiwu. The ecliptic longitude of the sun is 150°. At this time, the heat of summer has ended. The heat is about to dissipate. It is a turning point in the temperature drop. It is a symbol of cooler weather and the end of summer.

Bailu: Douzhigui. The solar longitude is 165°. The weather is getting cooler and condensation is forming on the ground.

Autumnal Equinox: Fighting fingers are over. The ecliptic longitude of the sun is 180°. On the autumnal equinox, just like the spring equinox, the sun shines almost directly on the equator, and day and night are almost equal. From this day on, the position of direct sunlight continues to move from the equator to the southern hemisphere, and the days in the northern hemisphere begin to become shorter and the nights longer. According to the autumn theory of our country's old calendar, this day is exactly half of the ninety days of autumn, so it is called the autumnal equinox. But according to astronomical rules, autumn in the Northern Hemisphere begins at the autumnal equinox.

Cold dew: fighting nails. The solar longitude is 195°. After the white dew, the weather turns cooler and dew begins to appear. When the cold dew arrives, there will be more dew days and the temperature will be lower. Therefore, some people say that cold is the air of dew, which is white first and then cold, which means that the climate will gradually turn colder. The water vapor condenses into white dewdrops.

Frost Descent: Douzhixu. The solar longitude is 210°. The weather has become cold and frost has begun, so it is called frost.

The beginning of winter: Douzhigan. The solar longitude is 225°. Traditionally, our people regard this day as the beginning of winter. Winter, as the meaning of end, means that the field operations of the year are over and the crops must be stored after harvesting. As soon as the Beginning of Winter is over, the middle and lower reaches of the Yellow River in my country will soon freeze, and farmers across the country will gradually turn to farmland water conservancy infrastructure and other agricultural activities.

Xiaoxue: Dou Zhiji. The solar longitude is 240°. The temperature dropped and snow began to fall, but it was not yet the time for heavy snowfall, so it was called light snow. Around the time of light snow, snow begins to fall in the Yellow River Basin (snowfall in the south is two solar terms later); while in the north, it has entered the freezing season.

Heavy snow: Dou Zhigui. The solar longitude is 255°. Before and after the heavy snowfall, snow gradually accumulated in the Yellow River Basin; in the north, it was already a severe winter with "thousands of miles of ice and thousands of miles of snow drifting".

Winter Solstice: Douzhizi. The solar longitude is 270°. On the day of the winter solstice, the sun shines almost directly on the Tropic of Capricorn. Our northern hemisphere has the shortest day and the longest night, and begins to enter the coldest days. This day is astronomically designated as the beginning of winter in the Northern Hemisphere. After the winter solstice, the direct sunlight position gradually moves northward, and the days in the northern hemisphere gradually become longer. As the saying goes: if you eat winter solstice noodles, one day will grow longer.

Xiaohan: Douzhizi, the yellow longitude of the sun is 285°. After Xiaohan, the cold season begins. Cold air accumulates for a long time and becomes cold. Xiaohan means that the weather is cold but not extremely cold.

Great Cold: Fighting refers to Chou, and the yellow longitude of the sun is 300°. Dahan means that the weather is extremely cold. The coldest season of the year is before and after the Great Cold. The Great Cold is just after the third nine and the beginning of the fourth nine. As the proverb goes: "Three, nine, forty-nine, walking on ice."

After the great cold, the beginning of spring comes and the weather gets warmer. At this point, the earth has orbited the sun once, completing a cycle.

Name meaning

The twenty-four solar terms are divided according to the position of the sun on the ecliptic (that is, the earth's orbit around the sun).

As the sun starts from the vernal equinox (zero degrees of ecliptic longitude, the sun shines vertically on the equator at this moment), every 15 degrees it advances is a solar term; it travels for one week and returns to the vernal equinox, which is a tropical year, totaling 360 degrees, so it is divided into 24 solar terms and precipitation phenomena. Indicates the time and intensity of rainfall and snowfall; the three solar terms of white dew, cold dew, and frost fall superficially reflect the phenomenon of water vapor condensation and sublimation, but in essence reflect the process and degree of gradual decline in temperature: when the temperature drops to a certain level, water vapor Condensation occurs; as the temperature continues to drop, not only does the condensation increase, but it also becomes cooler and cooler; when the temperature drops below zero degrees Celsius, the water vapor condenses into frost.

Function

The twenty-four solar terms reflect the climate changes throughout the year and help guide farmers in field farming.