How long is the rainy season How many days is the rainy season?

Due to the vagaries of the climate, it is not possible to determine the exact number of days, sometimes it is only a few days to over, sometimes it can be more than 1 month, but the general situation is usually about 20 days.

Generally in June-July. The plum rain is a unique weather and climate phenomenon in the middle and lower reaches of the Yangtze River in early summer, which is the result of the stagnation of the main rain belt in the Yangtze River basin in the process of northward migration of the main rain belt in eastern China. This change of seasons and the movement of the rain bands with the seasons are roughly the same from year to year, and a certain climatic regularity has been formed.

However, the rainy season is not exactly the same from year to year, and there is a large inter-annual variation. In meteorology, the time when the rainy season begins and ends are called respectively"Into the plum"(or.)"Limei"and"Out of the plum"(or.)"Broken plum"）。In the middle and lower reaches of the Yangtze River in China, the average plum enters in mid-June every year and comes out in early July, which lasts more than 20 days.

After the miscanthus planting, the first day of mold, after the summer heat, the first day of mold. The arrival of mildew is always between June 6 and 15, and the mold is always between July 8 and 19, and there is an obvious rainy season in eastern China with a long rainy period and relatively concentrated rainfall, which is caused by the north-south displacement of the main rainfall belt in the east-west direction, which is a unique phenomenon of the East Asian atmospheric circulation during the transition of the spring and summer seasons. After mid-June, the rain belt remains in the Jianghuai River Basin, which is the plum rain.

The duration of the rainy season is called the "rainy season", the day that begins the rainy season is called "Izume", and the day that ends is called "Izume".

In the Chinese almanac, there are records of the beginning and end of the mold rain: the beginning day is called "mold", and the end day is called "mold". After the miscanthus planting, the first day of mold, after the summer heat, the first day of mold.

The arrival of mildew is always between June 6 and 15, and the mold is always between July 8 and 19, and there is an obvious rainy season in eastern China with a long rainy period and relatively concentrated rainfall, which is caused by the north-south displacement of the main rainfall belt in the east-west direction, which is a unique phenomenon of the East Asian atmospheric circulation during the transition of the spring and summer seasons. After mid-June, the rain belt remains in the Jianghuai River Basin, which is the plum rain. The duration of the rainy season is called the "rainy season", the day that begins the rainy season is called "Izume", and the day that ends is called "Izume".

The "rainy season" is a climate phenomenon caused by the warm and humid air flow of the Pacific Ocean brought by the southeast monsoon in each month, passing through the middle and lower reaches of the Yangtze River in China, Taiwan, central and southern Japan, and southern Korea.

When the warm air of the summer monsoon makes landfall and moves northward to meet the cold air from the north to the south, the lighter warm and humid air is lifted above the cold air because the warm air is light and the cold air is heavy. Formed a frontal rain at the beginning of summer every year, the winter and summer winds in the middle reaches of the Yangtze River are evenly matched, this rain lingers here, the rain continues for as long as a month, because this is the ripening period of the plum in the south of the Yangtze River, so it is called "plum rain".

Causes

From late April to early May every year, the cold air from the north and the warm air from the south to the north converge in South China, forming a quasi-stationary front in South China. Around the end of May, the warm air strengthened, and the quasi-stationary front moved north to the Jianghuai region, becoming a quasi-stationary front (also known as the Meiyu front). As the warm air from the south carries a large amount of water vapour, a large amount of convective activity will occur when a colder air mass is encountered.

Due to the equal strength of cold and warm air during this period, the front stayed in the Yangtze-Huai region.

Typical rainy seasons are in mid to late June, and bloom in early to mid-July. The rainy season refers to the rainy season before the beginning of the plum season, which generally starts in mid-April and lasts for about half a month.

The standard of entering the plum is actually more complicated, but generally speaking, there are large rainfall areas in the middle and lower reaches of the Yangtze River basin and south of China, and there is a subtropical high near 20 degrees north latitude in the south to prevent the rain area from going south, causing the rainfall area to linger back and forth in the middle and lower reaches of the Yangtze River, and there is a long-term high-intensity rainfall. The weather situation has such a characteristic that it can almost be recognized as "entering the plum".

From the analysis of atmospheric circulation characteristics, usually starting in June, the subtropical high pressure over the Pacific Ocean intensifies, and in mid-June, the subtropical high stabilizes 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 the cold air in the north is not to be outdone, the cold air in the north and the warm and humid airflow in the south meet in the middle and lower reaches of the Yangtze River, forming a narrow and long rain belt. Generally in the first to mid-July, as the subtropical high strengthens again, the plum rain belt moves north to the area north of the Huai River, that is, "out of the plum", and after the "out of the plum" midsummer, it enters the dog days. Since the changes in atmospheric circulation vary from year to year, the "incoming" and "out-of-the-plum" are also different from year to year.

In terms of meteorology, the first day of rainy weather for more than 6-7 consecutive days and the average daily temperature of more than 22 degrees Celsius in early summer is generally the day of entering the plum season, and the day when the rainy season ends is called the day of the beginning of the plum season.

The so-called "entering the plum" time on the calendar is relatively fixed, and it is calculated according to the "dry branch day method", which is to take the first "C" day after the "mango seed" as "entering the plum", and the first "un" day after the "small summer" as "out of the plum". The time of "entering the plum" is always between June 6 and June 15, and the time of "entering the plum" is between July 8 and July 19.

Therefore, the meteorological "Ume" and the calendar "Ume" are not consistent in terms of time distribution, but in some years they may also happen to be together.

In the Chinese almanac, there are records of the beginning and end of the mold rain: the beginning day is called "mold", and the end day is called "mold". After the miscanthus planting, the first day of mold, after the summer heat, the first day of mold.

The arrival of mildew is always between June 6 and 15, and the mold is always between July 8 and 19, and there is an obvious rainy season in eastern China with a long rainy period and relatively concentrated rainfall, which is caused by the north-south displacement of the main rainfall belt in the east-west direction, which is a unique phenomenon of the East Asian atmospheric circulation during the transition of the spring and summer seasons. After mid-June, the rain belt remains in the Jianghuai River Basin, which is the plum rain. The duration of the rainy season is called the "rainy season", the day that begins the rainy season is called "Izume", and the day that ends is called "Izume".

In the middle and lower reaches of the Yangtze River in China, it is usually the rainy season from mid-June to early July every year.

The rainy season is every month.

The rainy season refers to a period of continuous rainy weather in the middle and lower reaches of the Yangtze River in China from mid-June to early and mid-July every year. At this time, the utensils are easy to mold, so it is also called "mildew rain", and it is also called "plum rain" or "yellow plum rain" when the plums in the south of the Yangtze River are ripe. The duration of the rain zone is called the "rainy season", and the day at the beginning of the rainy season is called "Imime".

From the Jianghuai River basin in China to the southern part of Japan, there is often a period of heavy precipitation in early summer (June to July) every year, and the number of precipitation is frequent. Because the plum is yellow and ripe, it is named. At this time, because of the high temperature, heavy humidity and rain, the utensils are easy to be damp and mildew, so it is called mildew rain.

Generally speaking, the plum blossoms are from early to mid-June, and the plums are from early to mid-July, and the midsummer begins after the plum blossoms.

Climatic Causes:

The formation of the rainy season is the result of the long-term stagnation of cyclones or fronts in the local area. Annually.

In May and June, the western Pacific subtropical high strengthened rapidly, and the hot and humid tropical ocean air mass and equatorial air mass took advantage of the momentum to expand to the Nanling area of China, and came into contact with the colder extratropical air mass from the north to form a front.

On the front, cyclones or troughs are constantly generated, and when these cyclones or troughs move eastward, they are often blocked by the high pressure along the coast of China, so they move slowly, and they have stayed in the southeast hills, the middle and lower reaches of the Yangtze River and the southern part of the Huaihe River basin for a long time, causing the formation of rainy and continuous plum rain in various places.