When is the rainy season?

Question 1: The standard of when plum rains usually enter plum blossom season is actually very complicated, but generally speaking, there are large rainfall areas in the middle and lower reaches of the Yangtze River and South China, and there is a subtropical high near 20 degrees north latitude in the south to prevent the rain area from going south, which causes the rain area to wander back and forth in the middle and lower reaches of the Yangtze River, resulting in long-term heavy rainfall. The weather situation has such characteristics that it can almost be considered as "entering the plum blossom".

From the analysis of atmospheric circulation characteristics, the subtropical high over the Pacific Ocean usually increases in June, and by mid-June, the subtropical high is stable over South China, and the southwest warm and humid airflow on its north side extends to the south of the Yangtze River. At this time, the power of cold air in the north is not to be outdone. The cold air in the north meets the warm and humid air in the south in the middle and lower reaches of the Yangtze River, forming a long and narrow rain belt. At this time, the plums in the south of the Yangtze River are ripe, and the people call the continuous rainy weather during this period "Meiyu", which is the beginning of Meiyu. Generally, in the first half of July, with the subtropical high strengthening again, the Meiyu belt moved northward to the north of Huaihe River, meaning "plum blossom". After Plum Blossom, it began in midsummer and entered the dog days. Because the atmospheric circulation changes differently every year, the "plum blossom" and "plum blossom" are different every year.

Meteorologically speaking, the first day when the continuous rainy weather in early summer exceeds 6-7 days and the daily average temperature exceeds 22 degrees is called plum blossom day, and the day when the continuous rainy weather ends is called plum blossom day.

In the calendar, the so-called "time of entering Mei" is relatively fixed and is calculated according to the method of "diary of branches and branches". It takes the first "C" day after the "canopy" as the "plum blossom" and the first "non-"day after the "light summer" as the "plum blossom". The time of "entering Mei" is always between June 6th and June 15, and the time of "leaving Mei" is between July 8th and July 19.

Therefore, the weather "entering Mei" and the calendar "entering Mei" are inconsistent in time distribution, but they may just be together in some years.

Question 2:2065 438+05 When does the southern rainy season start? Generally, Meiyu (Huangmeitian) begins in the middle and late June, which refers to the climate phenomenon of rainy days in the middle and lower reaches of the Yangtze River, Taiwan Province Province, south-central Japan, South Korea and other places from the middle and late June to the early July every year. This period is the mature period of plums in Jiangnan, so it is called "Meiyu".

Question 3: When will 2065438+06 enter the rainy season?

Meiyu, also known as Huangmeitian, refers to a cloudy and rainy natural climate phenomenon in the middle and lower reaches of the Yangtze River, Taiwan Province Province, south-central Japan and south Korea every year from the middle and late June to the first half of July. Because plum rains occurred in the mature period of plums in the south of the Yangtze River, people in China call this climate phenomenon "plum rains", and this period is also called "plum rains season". In rainy season, the air humidity is high and the temperature is high, so clothes are prone to mildew, so some people call the rainy season "the basis of mildew". After the rainy season, the weather in Central China, South China, Taiwan Province Province and other places began to be dominated by the Pacific subtropical high, and officially entered the summer heat.

Time law of occurrence

normality

The beginning date of plum rain is "entering plum" (or "falling plum") and the end date is "leaving plum" (or "breaking plum"). Generally speaking, the higher the latitude, the later the meiyu begins. Plum blossoms in Taiwan Province Province are in full bloom in mid-May and mid-June. In the middle and lower reaches of the Yangtze River in China, plum blossoms enter in mid-June and come out in early July on average. But there are some differences in specific places. In Zhejiang, plum blossoms enter the plum blossom in May of the lunar calendar. Specifically, plum blossoms enter the plum blossom in the morning after the awning, and they rise on the solstice of summer.

abnormal

The plum rain range, duration and rainfall of Prunus mume vary greatly from year to year. In some places where there should be plum rain, if there is no plum rain in some years, this phenomenon is called empty plum. After the rainy season, it usually clears up and enters the hot summer. If it turns rainy again at this time and lasts for a long time, it seems that it has returned to the plum season, which is called "heavy plum". There is a folk proverb, "Little summer thunder, plum blossom fragrance". In early summer, there are often long rainy days in the Jianghuai basin. At this time, the object is easy to be moldy, so it is also called "mildew rain", referred to as Meiyu Huangshan.

"mildew"; It is also called "Plum Rain" or "Huang Meiyu" because plums in the south of the Yangtze River are yellow and ripe. It is recorded in China's historical records. For example, The Book of Beginners quoted the compilation of Emperor Liang Yuan in the Southern Dynasties, "Plum blossoms have plum rains when they are ripe". Liu Zongyuan's Plum Rain in the Tang Dynasty: "Shi Mei welcomes the rain, and it is worth the late spring." Wait a minute. It is recorded in China's almanac that there is mildew rain all day: it is called "mildew" at the beginning and "mildew" all day long. The first day after the awn is planted, it is moldy, but it is not moldy on the first day after the hot summer. Mold always enters between June 6~ 15 and leaves between July 8~ 19. There is an obvious rainy season in the eastern part of China, with a long rainy period and relatively concentrated rainfall, which is caused by the displacement of the main rain belt from east to west to north, and is a unique phenomenon in the turn of atmospheric circulation in East Asia at the turn of spring and summer. After mid-June, the rain belt remained in the Jianghuai basin, which is Meiyu. The time that the rain belt stays is called "Meiyu season", the day when the rainy season begins is called "entering the plum blossom", and the day when it ends is called "emerging the plum blossom". In addition, due to the high humidity in the air during this period, everything is easy to be damp and moldy, so people gave Meiyu an individual name, called "Moldy Rain". Xie Zaihang's Five Miscellaneous Torches in Ming Dynasty? "Tianbu No.1" describes: "Every year in March and April in the south of the Yangtze River, it rains bitterly, and everything is moldy, commonly known as Meiyu, and it is covered when it is green and yellow. From Xu Huai to the north, it is often dry in spring and summer. At the turn of June and July, it rained heavily and everything was moldy. " Li Shizhen, an outstanding medical scientist in Ming Dynasty, pointed out more clearly in Compendium of Materia Medica: "Plum rain or mildew rain, when it comes to clothes and things, will produce black mold." .

Question 4: When is the rainy season in the middle and lower reaches of the Yangtze River in China? The rainy season is from late June to early July every year. At this time, the sky was overcast and the precipitation continued. In ancient times, there was a proverb that "rain hits Huangmeitou, and there is no sun for forty-five days", which is characterized by high temperature and high humidity in rainy season. Not only that, coastal cities in South China will also be hit by typhoons, and the weather and humidity will increase, making clothes and furniture more prone to mildew.

Plum entry: if the average temperature exceeds 22℃ for five consecutive days and it rains for four consecutive days, it is considered as plum entry.

Plum blossom: On the contrary, if the temperature exceeds 30℃ for five consecutive days and it doesn't rain, it means plum blossom.

Therefore, the rainy season also depends on the weather, and there is no specific time setting.

Question 5: The rainy season in southern China refers to the rainy weather that often lasts for a long time in early summer in the Jianghuai basin. At this time, the utensils are easy to be moldy, so it is also called "moldy rain" or "mildew" for short; When plums in the south of the Yangtze River turn yellow and mature, they are also called "Plum Rain" or "Huang Meiyu".

The middle and lower reaches of the Yangtze River in China are usually rainy from mid-June to early July every year. In the past few days, the sky has been gloomy and the precipitation has been constant, sometimes big and sometimes small. Therefore, there is a popular proverb in southern China: When the rain hits Huangmei's head, there will be no sun for forty-five days. Continuous rain, high temperature and high humidity are the main characteristics of plum rain.

Calculation method:

According to the principle of combining circulation conditions with regional precipitation, from late May to early July, the ground peak activity is frequent within the range of 29-33 north latitude, with six rainy days for two consecutive periods. At the same time, referring to the lower reaches of the Yangtze River, the average temperature of each station is basically stable above 22℃, which is the start date of entering Mei. In the time curve of rainy days, rainfall, cloud cover and other climatic factors in early summer, there are also days that suddenly increase (that is, there is a turning point), which is regarded as the average plum blossom period.

Traditionally, in China, the judgment of plum entry and plum exit is based on the combination of solar terms and branches. According to the calendar, the first third day after mango seeds is plum blossom, and the first last day in Xia Hou is plum blossom. If the weather on the awning day is C, it is designated as entering the plum blossom, and if it is not in the shallow summer, it is designated as leaving the plum blossom.

In ancient China, there were several rules for entering Mei. In trivial records, "(Min people) entered Mei on Geng Day in Xia Hou." "Shenshu Jing": "After the awn is planted, it will enter the plum in three days." "Jiangnan Record": "Plant mangoes in May, and meet your wife and enter Mei." "Tian Wu Jia Xing": "The rain after the awn seed is Huang Meiyu", and the awn seed is considered as plum blossom. There are two reasons for the above differences: first, regional differences; Second, the date of entering Mei for many years often changes. In the almanac of our country, the saying of Shenshu Jing is adopted. In the weather analysis and forecast, it often refers to the day when the weather situation turns to Meiyu situation.

For example, on June 6, 2006, mango seeds will enter Mei on the same day. July 17 coincides with a weekend after the intense summer heat, so the plum blossom date in 2006 is July 17. Huangmeitian ***42 days.

Question 6: When is the rainy season? In March and April, the south often returns to Nantian. There is water everywhere in the house, and everything is easy to get moldy.

Question 7: When is the rainy season in Guangzhou? The rainy season in Guangzhou is in April, May and June. The rainy season in Guangzhou is usually rainy. In the Jin Dynasty, there was a song "Summer Rain, hence its name". The interpretation of meteorological terms refers to a rainy weather from early summer to midsummer.

Question 8: When is the rainy season in Zhejiang this year? In the middle and lower reaches of the Yangtze River in China, plum blossoms enter in mid-June and come out in early July on average. But there are some differences in specific places. In Zhejiang, plum blossoms enter the plum blossom in May of the lunar calendar. Specifically, plum blossoms enter the plum blossom in the morning after the awning, and they rise on the solstice of summer. Meiyu weather in China is influenced by the western Pacific subtropical high. Every year in the middle and late June, the ridge line of subtropical high jumps northward and stabilizes at 20 ~ 25 degrees north latitude, and the rain belt moves northward, and the middle and lower reaches of the Yangtze River enter the rainy season. Because this time coincides with the yellow ripe plums, it is called Meiyu. However, from Monday to the beginning of June, Hangzhou and even the whole province did have a lot of rain, mostly process rainy weather. Because the current atmospheric circulation will be adjusted, the rain belt will continue to swing back and forth, which is not stable in the middle and lower reaches of the Yangtze River. Therefore, it is still too early to determine that Hangzhou will enter Mei in advance.

Question 9: Is it the rainy season now? When is the rainy season? It is already the rainy season, and June and July are the rainy seasons in the middle and lower reaches of the Yangtze River every year.

Question 10: When is the rainy season?

In early summer, there are often long rainy days in the Jianghuai basin. At this time, the utensils are easy to be moldy, so it is also called "moldy rain" or "mildew" for short; It is also called "Plum Rain" or "Huang Meiyu" because plums in the south of the Yangtze River are yellow and ripe. It is recorded in China's historical records. For example, The Book of Beginners quoted the compilation of Emperor Liang Yuan in the Southern Dynasties, "Plum blossoms have plum rains when they are ripe". Liu Zongyuan's Plum Rain in the Tang Dynasty: "Shi Mei welcomes the rain, and it is invaluable in late spring." Wait a minute. It is recorded in China's almanac that there is mildew rain all day: it is called "mildew" at the beginning and "mildew" all day long. The first day after the awn is planted, it is moldy, but it is not moldy on the first day after the hot summer. Mold always enters between June 6~ 15 and leaves between July 8~ 19. There is an obvious rainy season in the eastern part of China, with a long rainy period and relatively concentrated rainfall, which is caused by the displacement of the main rain belt from east to west to north, and is a unique phenomenon in the turn of atmospheric circulation in East Asia at the turn of spring and summer. After mid-June, the rain belt remained in the Jianghuai basin, which is Meiyu. The time that the rain belt stays is called "Meiyu season", the day when the rainy season begins is called "entering the plum blossom", and the day when it ends is called "emerging the plum blossom".

In addition, due to the high humidity in the air during this period, everything is easy to be damp and moldy, so people gave Meiyu an individual name, called "Moldy Rain". Xie Zaihang's Five Miscellaneous Torches in Ming Dynasty? "Tianbu No.1" describes: "Every year in March and April in the south of the Yangtze River, it rains bitterly, and everything is moldy, commonly known as Meiyu, and it is covered when it is green and yellow. From Xu Huai to the north, it is often dry in spring and summer. At the turn of June and July, it rained heavily and everything was moldy. " Li Shizhen, an outstanding medical scientist in Ming Dynasty, pointed out more clearly in Compendium of Materia Medica: "Plum rain or mildew rain, when it comes to clothes and things, will produce black mold." .

Meiyu and rain belt

The middle and lower reaches of the Yangtze River in China are usually rainy from mid-June to early July every year. In the past few days, the sky has been gloomy and the precipitation has been constant, sometimes big and sometimes small. Therefore, there is a popular proverb in southern China: When the rain hits Huangmei's head, there will be no sun for forty-five days. Continuous rain, high temperature and high humidity are the main characteristics of plum rain.

Very different from the climate in the same latitude area, Meiyu refers to the weather and climate phenomenon that occurs in a certain area and a certain season. It is found that Eurasia is between 20 N and 40 N, which is alternately controlled by subtropical high and westerly belt. The west coast of the mainland is controlled by the downdraft on the east side of the subtropical south pressure in summer, with sunny weather, partly cloudy and dry climate; In winter, under the influence of westerlies, warm and humid air is brought from the Atlantic Ocean, resulting in more precipitation and a mild and rainy climate. That is, the subtropical Mediterranean climate is dry in summer and humid in winter.

The east coast of the mainland is controlled by the west side of subtropical high in summer, and the downward flow is dry, but it absorbs a lot of water vapor from the warm and humid sea surface, bringing abundant precipitation and producing a subtropical humid climate. Due to the strong contrast between land and sea, a unique monsoon climate has formed here, which is characterized by rainy summer and dry winter, with rainfall concentrated in summer, which is just the opposite of the Mediterranean climate.

If compared with the east coast of Britain at the same latitude, it is also very different. There will be no rainy weather for a long time before and after the summer monsoon in the mid-latitude zone of the east coast of the United States, and people do not feel the feeling of sultry weather for a long time, so it is difficult to appear moldy. It can be seen that the precipitation season at the same latitude varies greatly. So there are only Huangmei in the middle and lower reaches of the Yangtze River in China, starting from the area east of Yichang and 29-33 degrees north latitude, as well as the southeast of Japan and the southernmost tip of the Korean Peninsula. In other words, Meiyu is a unique weather and climate phenomenon in East Asia and the middle and lower reaches of the Yangtze River in China.

2. Rain belt

Although Meiyu is a unique weather and climate in the middle and lower reaches of the Yangtze River, its appearance is not isolated, but closely related to the north-south displacement of a large-scale rain belt.

In the east of China, east of 1 10E, during the flood season from mid-May to early June, the main rain belt swings in Nanling Mountains and its south. In recent years, although it moved to the north of Nanling within a certain period of time, it often stayed in the south of 28N and 29° n from a waiting period (5 days) or the multi-year average of 10 days. This period is called Jiangnan rainy season or South China pre-flood season.

In the middle and late June, the main rain belt moved northward within the range of 29° n-33° n (that is, Yichang in the west, the Yangtze River estuary in the east, and then across the sea to Japan; From the south of China Lake Basin to the south bank of Huaihe River), it is stable and less active. At this time, the area south of Nanling has been outside the rain belt, and it has been raining for days ... >>