What do the 24 solar terms mean?

How are the 24 Solar Terms determined?

The Earth rotates around the Sun every 365 days, 5 hours, 48 minutes and 46 seconds, and once every 24 hours. Because the Earth's rotating orbital plane and the equatorial plane is not the same, but to maintain a certain tilt, so the direct sunlight to the Earth's position is different at all times of the year. In terms of the northern hemisphere, the sun directly at 23.5 degrees north latitude, astronomically known as the summer solstice; the sun directly at 23.5 degrees south latitude is called the winter solstice; summer solstice and winter solstice that is, has been to the middle of the summer and winter seasons. Twice a year when the sun is directly above the equator, the equinoxes and equinoxes, respectively, which is the middle of the spring and fall seasons, the two days of day and night are as long as.

The eight solar terms that reflect the changes of the four seasons are: spring, spring equinox, summer, summer solstice, autumn, fall equinox, winter and winter solstice. Among them, the spring, summer, fall, winter is called "four", indicating the beginning of the four seasons. Reflecting changes in temperature, there are five solar terms: Xiao Xia (小暑), Da Dian (大署), Shi Shi (处暑), Xiao Han (小寒) and Da Han (大寒). Reflecting weather phenomena, there are 7 solar terms: rain, rain, white dew, cold dew, frost, light snow, heavy snow. Reflecting the phenomenon of climate, there are four solar terms: hibernation, Qingming, Xiaoman, and Mangseo.

Meaning of the 24 Solar Terms

Liqiu: Li means beginning. Lichun is the beginning of spring. Rain: rainfall begins, and the amount of rain increases gradually. Hibernation: Hibernation means hiding. Hibernation means the first stirring of spring thunder, which awakens animals hibernating in the earth. Vernal Equinox: Equinox means equal division. Vernal Equinox means the equal division of day and night. Qingming: the weather is clear and the grass and trees are flourishing. Grain Rain: Rain produces all kinds of grains. With sufficient and timely rain, cereal crops can thrive. Lixia: the beginning of summer. Xiaoman: Summer crops such as wheat become full of seeds. Mang seed: wheat and other awned crops mature. Summer solstice: the hot summer is coming. Xiaoshu (小暑): summer means heat. Xiao Xiaoshu is the beginning of hot weather. Dazhong: The hottest time of the year. Autumn: the beginning of fall. Shi Xia (处暑): Shi means to end, to hide. The first heat is the end of the hot summer days. White Dew: the weather turns cooler and the dew condenses and turns white. Autumn Equinox: The equal division of day and night. Cold Dew: The dew is cold and will freeze. Frost: the weather gets colder and frost begins to form. Winter: the beginning of winter. Light snow: snow begins to fall. Heavy snow: snowfall increases and snow may accumulate on the ground. Winter Solstice: Cold winter is coming. Little Cold: the climate starts to get cold. Big Cold: the coldest time of the year.

What is "Sanjiu"? "Why is it the coldest time of the year?

"Sanjiu" refers to the third nine days after the start of winter, around mid to late January. "Why is it the coldest day of the year? This is to be absorbed from the ground at that time and the amount of heat emitted from the point of view, although the winter days are short at this time, the ground absorbs the least amount of solar heat, but at this time the ground emits more heat than absorbed heat, the air temperature near the ground to continue to go down when the ground absorbed to the sun's heat is almost equal to the ground emitted heat, the air temperature only to reach the coldest. To "three nine" later, the ground will absorb more heat than the ground heat loss, the air temperature near the ground also gradually rise. Therefore, the coldest time of the year generally appears in the winter solstice after the "three nine" before and after.

What is "three volts"?

The "three ambushes" are the first, middle and last ambushes, which occur from mid-July to mid-August. After the summer solstice, although the day grows shorter and the night grows longer, the day is still longer than the night, and the heat absorbed by the ground every day is still more than the heat emitted, so the temperature near the ground is also higher than the day. To the "three volts" period, the ground absorbs almost less heat than the heat emitted, the weather is also the hottest. After that, the amount of heat absorbed by the ground starts to be less than the amount of heat emitted from the ground, and the temperature slowly decreases. So the hottest time of the year usually occurs at the summer solstice in the "three volts".

Lichun

Since the Qin Dynasty, China has been using Lichun as the beginning of spring. Lichun is divided astronomically, while in nature and in people's minds, spring is warmth and the sound of birds and flowers; spring is growth and plowing and sowing. In climatology, spring is the period of time when the average temperature ranges from 10℃ to 22℃.

When it comes to the beginning of spring, people obviously feel that the days are longer and the sun is warmer. Temperature, sunshine, rainfall, this time often at the turning point of the year, tend to rise or increase. Small spring crop growth accelerate, rapeseed moss and wheat plucking when water consumption increases, should be timely watering and fertilizer to promote growth. Farmer's proverb reminds people: "spring rains, early rise and late to sleep," the spring preparations for plowing has also begun. Although the "spring", but most areas of the basin will still have frost, a few years there will be "snow but too late for spring, so through the garden trees as flowers" scene. These climatic features should be taken into account when arranging agricultural production.

People often love to look for spring information where? The willows on the buds, "tender in gold soft in silk"; the soil in the grass, waiting for the "spring breeze blowing again"; and to seize the new harvest in the fields of hard labor, people are using their hands to create a real spring.

Rain

The meaning of the rainy season is the beginning of rainfall, the amount of rain gradually increasing, in the Yellow River basin, the origin of the twenty-four seasons, the weather before the rain is cold, but see the snowflakes flying, it is difficult to hear the sound of rain pattering. After the rain, the temperature generally rises above 0 ℃, and the snow decreases while the rain increases. But in the warm climate of the Sichuan Basin, even in mid-winter, rainfall is not rare. Basin of our province during this period of time, the average temperature is more than 10 ℃, peach and plum buds, cherry blossoms, indeed to enter the climate of spring. Except for a few years, the frost period to this end. Grafting fruit trees, reforestation, it is time. Basin following the winter dry, perennial spring drought, especially in the western part of the basin is "spring rain is as expensive as oil". Agriculture should pay attention to moisture conservation, timely watering to meet the wheat plucking pregnant spikes, rapeseed moss blossom water critical period of water supply. Western Sichuan plateau mountains are still in the dry season, the air temperature is small, wind speed, prone to forest fires. In addition, the cold wave invasion can cause strong cooling and blizzard, the old, weak, young animals are very harmful. All of these, special attention should be paid to prevention.

Light time passes easily, the season rushes people, "a year's plan is in the spring". Small spring management and spring preparation for plowing should be carried out urgently, and strive to win this year than in previous years.

Hibernation

Reflecting the natural phenomenon of hibernation, meaning: the first movement of the spring thunder, awakening the hibernation in the soil hibernating animals. At this time, the temperature rises faster, the Yangtze River Basin, most areas have been gradually spring thunder. The eastern part of the basin of our province and the southern part of Liangshan Prefecture, perennial rain, hibernation can also be heard at the beginning of the spring thunder; and the northwestern part of the basin, in addition to individual years, generally until the Qingming only thunder, the beginning of thunderstorms for the province's latest region.

To the hibernation, most of our country into the spring plowing season. Really: the season does not wait for people, a moment worth a thousand dollars. The basin of our province, the average temperature of the hibernation season is generally 12 ℃ to 14 ℃, more than 3 ℃ higher than the rainy season, is the fastest temperatures throughout the year. The number of hours of sunshine also has a relatively obvious increase. However, because of the alternation of cold and warm air, the weather is unstable and the temperature fluctuates greatly. Basin southeast of the Yangtze River Valley area, most years during the shock of the temperature stabilized above 12 ℃, conducive to rice and corn sowing, the rest of the region is often more than three consecutive days of average daily temperature of 12 ℃ below the low temperature weather, can not be blindly early sowing. Although the hibernation temperature rises rapidly, but the increase in rainfall is limited. The central and northwestern part of the basin during the hibernation rainfall totaled only about 10 millimeters, following the perennial winter dry, spring drought often began to show its head. At this time, wheat spikes, rape flowering are in the period of high water demand, sensitive to water requirements, spring drought often become an important factor affecting the yield of the spring. Tree planting should also take into account this climatic feature, after planting to be diligent in watering, and strive to improve the survival rate of saplings.

The hibernation season is a time of bright spring and renewal. Through careful observation, the accumulation of climatic knowledge, for the local arrangement of agricultural activities will be helpful.

Spring Equinox

The spring equinox is one of the festivals that reflect the changes of the four seasons. In ancient China, it was customary to indicate the beginning of the four seasons with the establishment of spring, summer, autumn and winter. The spring equinox, summer solstice, fall equinox and winter solstice are in the middle of the seasons. On the day of the equinox, the sun's rays directly on the equator, the day and night time around the earth are equal, so the ancient equinox is also known as the "day and night", folk "equinox and autumn equinox, day and night," the proverb.

After the spring equinox, most of the winter crops in most parts of China entered the spring growth stage. Central China has a "spring equinox wheat up, a moment worth a thousand dollars" of agricultural proverbs. Temperatures continue to rise across the province, but generally not as fast as the period from rain to the equinox. the average temperature in late March in the northern part of the basin is more than 13 ℃ to 15 ℃, the southern part of the basin is more than 15 ℃ to 16 ℃. Most areas of the plateau has been snow melt ice, the average temperature of the ten days about 5 ℃ to 10 ℃. The southwestern part of the province Jinsha River, Anning River and other river valleys have the highest temperature, the average has reached about 18 ℃ to 20 ℃. Basin, in addition to the edge of the mountainous areas, the average ten seven, eight years of average daily temperatures rise steadily to more than 12 ℃, conducive to rice, corn and other crops sown, reforestation is also very suitable. However, before and after the spring equinox basin often have a stronger cold air invasion, the temperature dropped significantly, the lowest temperature can be as low as 5 ℃ below. Sometimes there is a small cold air followed by the formation of a sustained days of low temperature and cloudy rain, which is unfavorable to agricultural production. According to this feature, should make full use of the weather forecast, seize the cold end of the warm head in time to sow.

Ching Ming

Ching Ming is a festival that characterizes the weather and means clear weather and lush grass. On this day, there are folk customs such as trekking, cold food, and sweeping graves.

As the saying goes, "Qingming breaks the snow, and Guyu breaks the frost." When it comes to Qingming, the basin has a warm climate and spring is in full swing. But before and after the Qingming, there are still cold air invasion, and even make the average daily temperature for more than three consecutive days below 12 ℃, resulting in rotten rice seedlings and early rice seedlings, so rice sowing, planting to avoid the warm end of the cold head. In the western Sichuan plateau, livestock by the harsh winter and the impact of grass shortage, resistance is weak, need to guard against the strong cooling weather in the spring on the old and weak young animals.

"It's raining at the time of the Qingming Festival," said Du Mu, a famous Tang Dynasty poet who wrote about the spring rains in Jiangnan. But in the case of Sichuan, this is not the case. Especially in the western part of the basin, often in the spring drought period, the rainfall in early April is generally only 10 to 20 millimeters, is still less than half of the belt of Jiangnan; the eastern part of the basin, although the spring rain is more, but the rainfall in early April is generally no more than 20 to 40 millimeters, the natural precipitation is also not enough for the needs of agricultural production must rely on the previous year, storage of water to replenish. In addition, April is the most hailstorm month of the year in Liangshan Prefecture, should strengthen the defense of hail.

Grain rain

As the saying goes: "Rain produces a hundred grains". With sufficient and timely rain, cereal crops can thrive. The Grain Rain festival has this meaning.

Sichuan Basin during the rainy season, "poplar flowers fall out of the Zigui cries", willow waddles fly down, azaleas cry at night, peonies spit stamens, cherries red ripe, the natural scenery notice people: it is time to the late spring. At this time, the basin's temperature rises faster, the average temperature in late April, in addition to the northern and western parts of the basin, has reached 20 ℃ to 22 ℃, higher than the middle of 2 ℃ or more. The eastern part of the basin will often have one or two days of high temperatures above 30, so that people begin to feel the heat. Southwest Sichuan low altitude valley area industry to enter the summer. Basin spring temperatures higher climate characteristics, in favor of the spring crop cultivation measures to grasp early. Suitable for red camas planting temperature of 18 ℃ to 22 ℃, this time has been able to meet. The experience of the old dry areas of the basin proved that the red camas planted early after the rains, can make the vine leaves before the drought to seal the compartment, enhance the drought-resistant ability, get high yield and stable yield.

The eastern part of the basin in our province at this time the rain is more abundant, perennial rainfall in late April about 30 to 50 millimeters, the first annual downpour generally appear in this period, rice planting and corn, cotton seedling growth is favorable. However, most of the rest of the basin receives less than 30 millimeters of rain, requiring irrigation measures to mitigate the effects of drought. In the mountains of the western Sichuan plateau, which are still in the dry season, precipitation is generally only 5 to 20 millimeters. Basin rainfall before and after the rain, often "with the wind into the night, moist and silent", "Bashan night rain" in April and May to appear the most opportunities." Shu day often night rain, river threshold has been clear", this night rain day clear weather, on the spring crop growth and small spring crop harvest is quite suitable.

The beginning of summer

As the name suggests, the beginning of summer means the beginning of summer. However, the timing of the start of summer is actually not consistent, as it varies from place to place. According to the climatology of the five-day average temperature higher than 22 ℃ for the summer standard, before and after the summer, the southern Sichuan Basin has just crossed into the summer; the rest of the basin temperature of 20 ℃ or so, is still in the "no one outside the door to ask about flowers, green shade Ran all over the end of the world" of the twilight of the spring; and southwest of the low-altitude valleys as early as early April in the beginning of the sense of the summer heat, when the summer has reached a temperature of 24 ℃ or more, can be described as the summer heat. Yiwei" summer "electricity see" said. But in terms of Sichuan, even in the beginning of the most late in the northwestern part of the basin, perennial thunderstorms also began in April, in mid-April, "electricity to see" without having to wait until the summer.

After the summer, it is the basin in the rice planting large areas of the water needs of the critical period, the rain comes sooner or later and the amount of rain, and agricultural production is closely related. At this time, if not a larger rain, those without water irrigation farmland can not pear rake planting seedlings. According to climate statistics, the average period of the beginning of heavy rain over the years, the eastern part of the basin in mid-April, late, central in mid-May, late, western in late May. May rainfall in the southeastern part of the basin for the 100 to 200 millimeters, the northwestern part of the 75 to 100 meters. The western and central parts of the basin tend to have summer drought outcroppings because of the late start of heavy rains and low rainfall.

This period of time, just as the basin harvested small spring crops, sowing spring crops, especially pay attention to the impact of variable weather. Sunny days to harvest in a timely manner, rainy days should be planted in a hurry, rainy weather must be careful to prevent small spring harvest buds, mold, but also to do a good job of drought seedling, vigilant 20 ℃ below the low temperature on the hazards of early rice.

Small full

Twenty-four can be mostly named, but the small full is somewhat puzzling. As it turns out, Xiaoman refers to when summer crops such as wheat become milky and full of seeds. Sichuan basin of agricultural proverbs to give a new meaning to Xiaoman: "Xiaoman full, dry break Si Kan"; "Xiaoman full, regardless of Mangshan". The "full" is used to describe the surplus and deficit of rainwater, pointing out that if the field is not full of water at the time of the small full, it may result in the drying off of Sikan, and even the mango seeding can not be planted rice. Because of the "summer Xiaoman is planting rice seedlings", "rice seedlings run Xiaoman Valley run fall", Xiaoman is suitable for rice planting season. Basin of the summer drought serious or not, and rice planting area of how much, there is a direct relationship; and planting sooner or later, and rice yields are closely related to the high and low. The central and western basin, often dry winter and spring drought, the arrival of heavy rain and late, some years to June rain only came, the latest even as late as July. Coupled with the perennial Xiaoman Festival rainfall is not much, an average of only 40 millimeters or so, natural rainfall can not meet the amount of water needed to plant seedlings, making the lack of water in the central basin of the summer drought is more serious. As the saying goes: "store water like grain", "keep water like grain". In order to resist drought, in addition to improving farming and cultivation measures and accelerate afforestation, especially need to pay attention to the first year of water storage and water conservation work. However, it is also necessary to pay attention to the possible continuous rainy weather, the impact of small spring crop harvesting and sunshine. Western Sichuan plateau mountain area, this time more than has entered the rainy season, crop growth, thriving.

Mangseed

Mangseed characterizes the maturation of wheat and other awned crops, and is a festival that reflects the phenomenon of agricultural weather. In the Sichuan Basin, the wheat harvest season has passed, and the transplanting of rice and sweet pota beans is nearing its end. Most areas of rice into the stage of greening, seedlings tender green, a faction of vitality." The poem "The east wind has dyed three thousand hectares, and the herons have nowhere to stop" vividly depicts the beautiful scenery of the fields at this time.

To the mango season, the basin has not been transplanted in the rice, should be planted urgently; if delayed, due to increased temperatures, rice nutrient growth period is shortened, and the growth stage is susceptible to drought and pests, the yield will not be high. Red camas transplanted to the latest to catch up before the summer solstice; if planted camas too late, not only the impact of drought will be aggravated, but also to the fall when the temperature drops, is not conducive to the expansion of potatoes, the yield will also be significantly reduced. The reasoning behind the proverb "Busy planting" is here.

Summer solstice

Summer solstice this day, the sun is directly above the Tropic of Cancer, the northern hemisphere is the longest day of the year, Sichuan from sunrise to sunset most of the fourteen hours or so.

Summer solstice this although the longest day, the sun's highest altitude angle, but not the hottest time of the year. Because, the heat of the near-earth layer, this time is still continuing to accumulate, and has not reached the most when.

Over the summer solstice, the basin of our province, agricultural production due to crop growth, weeds, pests and diseases quickly grow and spread into the field management period, the high plateau pastoral areas began the golden season of grass fertilizer and animal prosperous. At this time, the western part of the basin rainfall increased significantly, so that since the spring of the basin rainfall east more west less distribution situation, gradually changed to west more east less. If there is a summer drought, generally this time can be expected to lift. Nearly three decades, the western part of the basin in late June, although the number of large-scale flooding, but the degree is more serious. Therefore, special attention should be paid to flood preparedness. Summer solstice is the eastern part of the basin the most rainfall throughout the year, often controlled by the subtropical high pressure, drought. In order to enhance the drought resistance, to seize the agricultural harvest, in these areas, to save the rain before the ambush is an important measure.

After the summer solstice, the ground is heated strongly, the air convection is strong, the afternoon to evening is often easy to form thunderstorms. This heat thunderstorms suddenly come and go, rainfall range is small, people called "summer rain across the field". Tang Dynasty poet Liu Yuxi in Sichuan, had clever metaphor this weather, wrote "east side of the sunrise west side of the rain, the road is not clear but there is a sunny" of the famous poem.

Small summer

Small summer in the Sichuan basin. The average temperature in the Sichuan Basin during the summer is about 26 degrees Celsius, which is already the height of summer and quite hot, but not yet the hottest time. Perennial mid-July, the basin southeast of the low-altitude valley area, can begin to appear the average daily temperature is higher than 30 ℃, the highest daily temperature is higher than 35 ℃ of the concentration of time, which is unfavorable to hybrid rice spike flower. In addition to the layout in advance should be fully considered on this factor, has been planted to take appropriate remedial measures. In the northern part of the western Sichuan plateau, this time is still visible frost and snow, equivalent to the basin early spring scene.

Before and after the summer, the western part of the basin into the most torrential rainfall season, the number of days of rainstorms in July and August of the year can account for more than 75% of the year, usually about 3 days. In places where the terrain is more undulating, there are often flash floods, and even cause mudslides. But in the eastern part of the basin, after the summer, often controlled by the subtropical high pressure, more sunny and hot weather, began to enter the drought period. The basin of our province this east drought and flooding of the climate characteristics of the west, and agricultural abundance and failure of the relationship is very large, must be taken early drought, flood control measures to minimize the harm.

Before and after the summer, our province around the most thunderstorms into the season. Thunderstorms are a violent weather phenomenon, often accompanied by gusty winds, rainstorms, and sometimes hail, easy to cause disasters, must also pay attention to prevention.

The Great Heat

Summer means heat. It means that it is the hottest season of the year.

Generally speaking, the Great Summer Festival is the period of the year in the basin with the most sunshine and the highest temperature, the most abundant rainfall in the western part of the basin, the most common thunderstorms, the most concentrated number of days with high temperatures of more than 30 degrees Celsius, as well as the eastern part of the basin, where high temperatures of more than 35 degrees Celsius occur most frequently.

High temperatures before and after the summer is a normal performance of the climate, because higher temperatures are conducive to the spring crop flowering and grouting, but the temperature is too high, crop growth is instead inhibited, the rice fruiting rate decreased significantly. The western part of the basin into the ambush, light, heat, water are at the peak of the year, the three promote each other, the formation of spring crop growth of good weather conditions, but need to pay attention to flood prevention and drainage. The eastern part of the basin at this time of high temperature and long sunshine but often accompanied by little rain, will not only limit the play of the advantages of light and heat, but also exacerbate the adverse effects of drought on spring crops, in order to resist drought, in addition to the early attention to the storage of water, should also be based on the eastern part of the basin's climatic characteristics, to improve crop cultivation measures, based on the "early" in order to tend to the benefits of avoiding the harm.

The heat of the summer is the jasmine, lotus blooming season, fragrant jasmine, the hotter the weather, the stronger the fragrance, giving people clean and fragrant enjoyment. Clean lotus, defying the scorching sun and rain, morning and evening convergence, the poet praised it, "reflecting the sun lotus red", vibrant summer, is pregnant with a good harvest.

Autumn

"The cool winds of the day of autumn" clearly connects autumn with the coolness of the sky. It can be seen that the beginning of autumn is the beginning of the cooler fall season. Due to the differences in latitude and altitude, it is not possible to enter the fall season at the same time on the day of the beginning of autumn. In accordance with the climatology of the weather (5 days) average temperature between 10 ℃ and 22 ℃ for spring, fall standards, in addition to those latitudes north and higher altitudes in China, more than the beginning of autumn, still in the summer, even in most areas of the Northeast, this time can not be seen in the cool winds, the yellow leaves of the autumn scenery. For the Sichuan Basin is located in the central subtropical, perennial summer in August is still heavy. Climate statistics show that the basin to the middle of September, late Fang only successively into the fall; in the whole year are winter or winter long no summer, spring and autumn connected to the plateau and alpine areas, can not say what time the beginning of the fall.

After the fall, the basin of our province, late rice plucking pregnant spike, cotton bolls spitting fluff, can not relax field management; rice, summer corn into the grout maturity stage, beware of hail, wind, rainstorms. East and west of the basin, respectively, should continue to do a good job of drought, flood control. Autumn after the basin, although the season is still summer, but "autumn ten days all over the yellow" a golden "autumn" is coming.

Summer

Summer is a season that reflects the change in temperature. The word "处" means "to hide" or "to end", and "处暑" means the end of the hot summer days.

The average temperature in the basin of our province is generally lower than the autumn about 1.5 ℃, individual years in late August in the western part of the basin there may be more than three consecutive days of average daily temperature of 23 ℃ below the low temperature, affecting the flowering of hybrid rice. However, because the basin in the summer is still basically controlled by the summer winds, so there are still often higher than 30 ℃ maximum temperature in the western part of the basin, the eastern part of the basin is higher than 35 ℃ of the weather. Especially along the Yangtze River at low altitudes, in the continuation of the drought in the year, more feel the "autumn tiger" aftermath. Western Sichuan Plateau into the summer autumn is thick, the altitude of 3500 meters above the early winter has been the scene, the pasture gradually withered, frost and snow increasing.

Summer is the basin of our province rainfall distribution from the west more east less to the east more west less conversion of the early period. At this time the central basin rainfall is often the second highest point of the year, more than in the summer or white dew. Therefore, in order to ensure that the winter and spring farmland water, must seriously grasp the water storage work during this period. Plateau region of the summer to the autumn equinox will appear continuous rainy weather, the ground agriculture and animal husbandry production is not favorable. The basin of our province at this time is also the harvest of rice in the busy season. In general, the year of the summer festival, the basin is still relatively abundant sunshine, in addition to the western part of the basin, not many rainy days, conducive to the rice cut sun and cotton spit flocculent. However, in a few years, there are as Du Shi said. The three volts of the appropriate has passed, the sun into rain" of the scene, the autumn rain will come early. So pay special attention to the weather forecast, be well prepared, seize every good weather, lose no time to do a good job of harvesting and sunshine.

White Dew

Dew is a droplet of water that condenses on the ground or near-earth objects due to lower temperatures. Therefore, white dew actually symbolizes that the weather has turned cooler.

In the twenty-four seasons of the climate in the basin of our province, the white dew has a rapid decline in temperature, the beginning of rain, sunshine, the obvious characteristics of the sudden decrease, a profound reflection of the seasonal transition from summer to autumn. Basin perennial white dew during the average temperature than the summer heat to be lower than about 3 ℃, most of the region wait (5 days) the average temperature has fallen below 22 ℃. According to the climatological division of the four seasons of the standard, the chronology began to enter the fall.

Basin fall rain mostly appeared in the White Dew to frost, to the Minjiang River, Qingyi River in the middle and lower reaches of the region most, the central part of the basin is relatively less." Abuse of the white dew, every day to walk the slippery road" of the farmers' proverb, although can not be white dew this day whether there is rain to make weather forecasts, but, in general, before and after the White Dew Festival does often have a period of cloudy weather; and, since then, the basin rainfall has more than the intensity of the small, rainy days, often the characteristics of the continuous rainfall. Correspondingly, the basin during the white dew sunshine than the summer plummeted by about half, the decreasing trend has continued into the winter.

White dew season of the above climate characteristics, on the late rice and cotton peach blossom is unfavorable, but also affects the rice harvest and turning, so the proverb has "white dew day air clear, rice white as silver," the saying. Fully understand the characteristics of the white dew climate, and take appropriate agronomic measures in order to reduce or avoid the harm of autumn rain. On the other hand, it is also necessary to take advantage of the rain to grasp the water storage, especially in the eastern part of the basin of the white dew is following the small full, summer solstice after another rainy season, do not miss a good time.

Autumn Equinox

The autumn equinox is a festival that characterizes the change of seasons. On the day of the autumnal equinox, the sun is located at 180 degrees of yellow longitude, the sun shines almost directly on the equator, and the day and night are almost equal in length. At this time, the Sichuan Basin, the candidate temperature generally dropped to 22 ℃ below, into the cool fall." An autumn rain is a cold." A strand of cold air from the south, and the gradual decline of warm and humid air, resulting in a rainfall, the temperature also fell again and again. In the northern part of the western Sichuan plateau, the daily minimum temperature fell to below 0 ℃, you can already see the sky flocculent fluttering, the earth wrapped in silver magnificent snow scene.

After the autumnal equinox, the province's rainfall significantly reduced, torrential rain, heavy rain generally seldom appear; however, the number of days of rainfall has increased, often rainy and cloudy, the rate of night rain is also higher. The famous Tang Dynasty poet Li Shangyin's famous line "Bashan night rain rises in the autumn pool" vividly depicts the climate characteristics of Sichuan's autumn night rain.

The basin of our province and Liangshan Prefecture have a lot of rain in the fall, and the moisture damage is serious, which has a great impact on the fall harvest, fall plowing and fall planting. To grab the sunshine harvesting and sunshine, moisture prevention, grasp the "three autumn" production quality and progress. At the same time, but also to make full use of the autumn rain, soil moisture better meteorological conditions, without losing time to engage in afforestation, and strive to improve the survival rate of saplings.

Cold dew

Anciently, the dew as a symbol of the weather turned cold. In the mid-autumn white dew festival, "dew condensation and white", to the seasonal autumn cold dew is "dew cold, will condense" for frost.

This time, the temperature continues to fall across the province. Basin average daily temperature more than less than 20 ℃, even in the Yangtze River coastal areas, the mercury is difficult to rise above 30 ℃, while the lowest temperature can fall below 10 ℃. Western Sichuan Plateau, except for a few river valley lowlands, wait (5 days) the average temperature is generally below 10 ℃, with the climatological division of the four seasons of the standard measure, it is already winter. Thousands of miles of frost lay, thousands of miles of snow, and the basin of the autumn color is very different.

Perennial cold dew period, the basin rainfall is also decreasing. The western part of the basin more than 20 millimeters above and below, the eastern part of the general 30 to 40 millimeters or so. Sheepish rain is very frequent, towards twilight, drizzling and falling, affecting the "three autumn" production, the basin of our province has become a catastrophic weather. Accompanied by rainy climate is characterized by: high humidity, cloudy, less sunshine, more cloudy days, foggy days have also increased significantly since then. However, the fall rain is serious or not, directly affect the "three autumn" progress and quality. To this end, on the one hand, to take advantage of the weather forecast, grab sunny days to harvest and sowing; on the other hand, we should also be adapted to local conditions, to take a deep ditch high compartment and a variety of effective farming measures to mitigate the wet damage, and improve the quality of sowing. In the plateau area, before and after the cold dew is one of the most serious snow season, snow blocking traffic, jeopardizing livestock production, should pay attention to prevention.

People will celebrate the annual traditional festival.

Frostfall

Frostfall festival contains the meaning of the weather is getting cold, the beginning of frost. In the Sichuan Basin, where the latitude is in the south, the average temperature is mostly around 16 degrees Celsius, and there are still three more festivals before the date of the first frost. In the southern valley of the basin, it will not see frost until mid-winter. Of course, even in the same latitude, due to the altitude and topography of the different, adhering to the stratum of air temperature and humidity there are differences in the period of the first frost and the number of frost days will not be the same.

With a scientific point of view, "dew for frost" is inaccurate. Frozen dew, made by the freezing of dew drops, is hard, small droplets of ice. Frost is due to a sharp drop in temperature caused by crop frost phenomenon, the damage caused by the temperature of crops, varieties and reproductive period of different; and the formation of frost, the ground or features must be the temperature drops to 0 ℃ or less, and stick to the stratum of the air in the water vapor content to a certain extent. Therefore, frost does not necessarily occur when frost occurs, and frost does not necessarily occur when frost occurs. However, because the temperature at the time of frost has been relatively low, if it continues to cool, it will easily lead to the occurrence of frost. After the frost, the basin of our province began to dig a large number of red camas. If digging too early, the pota has not yet fully expanded, will affect the yield; but digging too late, may suffer early frost damage, pota freeze deterioration, intolerance of storage, so the timely digging pota is very important.

Su Shi, a great writer of the Northern Song Dynasty, said in a poem: "Thousands of trees are swept into some yellow, only the hibiscus alone Fang." Sichuan Basin has a mild climate, and during the frost period, the fields are green, orange, yellow and green, and the autumn chrysanthemums are in bloom, and the hibiscus trees are in full bloom, which dresses up the rich "Heavenly Capital" in a more colorful way.

The winter

When it comes to "winter", it is natural to associate it with cold." The name "Li, Jianshi also," indicates that winter has begun since then." On the day of winter, the water begins to freeze, the ground begins to freeze." Now, people often use the bitter north wind, cold frost and snow, as a symbol of winter. The basin of our province is also scarce snow and frost, so, in climatology, not fixed to "winter" this day as the beginning of winter around, but the temperature to divide the season, that is, wait (5 days) the average temperature below 10 ℃ for the winter, so that the more section of the landscape at the time of the weather.

The winter season in the basin of our province, still in the "three autumn" busy period, the average temperature is generally 12 ℃ to 15 ℃. The rain has ended. Climatic conditions are suitable for oilseed rape transplanting. Growing period is shorter and stronger spring wheat should also catch sowing, because the late winter more strong cold air invasion, the temperature often has a large drop, if the sowing temperature is low, the seedling is slow, the split is not enough, it will affect the yield. Red camas in the average daily temperature below 15 ℃, growth has gradually stopped, should be harvested in time. Individual years in the northwestern part of the basin in the winter had an early frost, it is more important to dig the cellar early, free from frost damage. Plateau area this time has been the dry season, humidity is rapidly decreasing, wind speed is increasing, the forest fire risk must be highly vigilant.

Small snow

Small snow indicates the onset and extent of snowfall. Snow is a product of cold weather. During the Little Snow festival, winter begins in the northern Sichuan Basin." The lotus is no longer covered with rain, and the chrysanthemums are still frosty", which is the beginning of winter. Because of the north of the Qinling Mountains, the Daba Mountain barrier, blocking the invasion of cold air, brake reduction of the cold wave of the severity of the power, resulting in the basin, "winter warmth" significant. Snowfall days throughout the year, mostly in 5 days or less, than the same latitude of the Yangtze River in the lower reaches of the region much less. The chance of snowfall before the big snow is very little, even in winter, it is rare to see "thousands of pear blossoms" charming scenery. Because of the basin winter near ground level temperature is often kept above 0 ℃, so the snow than snowfall is not easy. Occasionally, although the sky "flurry", but do not see the ground "broken Qiong mess jade". However, in the cold western Sichuan plateau, perennial October generally began to snow. Northwestern plateau snowfall days can reach more than 60 days, some alpine areas throughout the year there is the possibility of snowfall.

During the period of light snow, the first frost is generally visible in the northwestern part of the basin, and it is important to prevent frost damage to crops. In the northern part of Gan and Aizhou, the lowest temperature is mostly around minus 15 degrees Celsius, and you should do a good job of preventing cold and keeping livestock warm.

Daxue

"Daxue" indicates that this is the time of year when snowfall begins to be heavy. Sichuan Basin winter climate is mild and less rain and snow, the average temperature of the middle and lower reaches of the Yangtze River is about 2 ℃ to 4 ℃ higher, the rainfall only accounted for about 5% of the year. Occasional snowfall, mostly in January and February; ground snow three or five years hard to see once. If you are able to witness the snow-covered terrain, green trees in silver jewelry jade, is often an unforgettable life-long fun.

"Snow is a sign of good fortune," is a widely circulated agricultural proverb. In the north, a thick and loose layer of snow, like to wheat cover the cold quilt. Nitrogen compounds contained in the snow than rain 4 times more, the snow slowly melted into the soil, can increase the nitrogen in the soil, easy to be absorbed by crops. Snow water temperature is low, can freeze the surface layer of the overwintering pests, but also bring benefits to agricultural production. However, in the south, after the snow, such as the sunny