What are the reasons for the sunny weather?

? This friend asked, "What is the reason for the sunny weather in Tomb-Sweeping Day?" To make this clear, we should say it together with the "Grain Rain" solar terms, because Tomb-Sweeping Day and Grain Rain are two closely related solar terms in spring, and proverbs are often put together, such as "It's sunny in Tomb-Sweeping Day, it's rainy in Grain Rain" or "It's sunny in Tomb-Sweeping Day and it's rainy in Grain Rain".

First, why do you say "clear"? As we know, Tomb-Sweeping Day is the penultimate solar term in spring, and the time is around April 5th in the Gregorian calendar. It's late spring. ? Qingming is coming, which is the key period for spring sowing crops to germinate and emerge. The germination and emergence of crops need suitable temperature, such as cotton temperature above 12℃, corn temperature above 10℃ and beans temperature above 8℃. Only when the temperature reaches the required index for crop growth can the smooth germination and emergence be guaranteed.

? Therefore, during the Qingming period, if the weather is good, the temperature will be higher and the seedlings will emerge faster. Therefore, "the sky is clear and the sun is shining." This mainly means that there should be a suitable temperature for crop germination and emergence at this time. The rainy weather at this time is usually accompanied by cooling. Therefore, if it rains, the temperature will drop, which will affect the germination and emergence of crops.

Second, why do you say "it will rain in Grain Rain"? It is best to be sunny during the Qingming Festival to ensure the appropriate temperature. When we enter the next solar term in Grain Rain, on the contrary, it needs rain.

? During the Qingming Festival, crops germinate and emerge. After entering Grain Rain, these crops, which have just emerged and are still in the seedling stage, need to be moistened by rain, because they need to take root and sprout at this time.

? At the same time, in Grain Rain season, winter wheat is also the jointing and booting stage, which requires sufficient water for irrigation. So it is said that "it will rain in Grain Rain" or "it will rain in Grain Rain".

Third, why do you say "Qingming will be sunny but not sunny, and Grain Rain will be drenched but not drenched"? "It will be sunny in Qingming, it will rain in Grain Rain" or "It will be sunny in Qingming, it will rain in Grain Rain", which is people's good wishes and places their hopes on the favorable weather in nature.

? However, unexpected events happen, and the changes in nature are independent of people's subjective will. Therefore, another phenomenon often appears in reality. The ancients also summed up a proverb, which is called "There will be sunny days in the Qingming Festival, and Grain Rain will never stop". It is also called "it is rare to have sunny days in Tomb-Sweeping Day and rainy days in Grain Rain", which means: it is best to have sunny days in Tomb-Sweeping Day, and it is rare to have good weather; It goes down to Grain Rain, but it seldom rains. This seems to be deliberately aimed at people.

? This phenomenon of "if it rains, it can't rain" is common in ancient poems. Here is an example:

? During the Qingming period, there was more rain; Rain flowers fly in Qingming Festival; It rains like silk during the Qingming Festival; The sound of rain in Tomb-Sweeping Day; Every cloudy day in Tomb-Sweeping Day; During the Qingming period, it was rainy and windy; During the Qingming period, there are many rains; During the Qingming period, rain produces cold; I am used to seeing clear rain every year; The east wind urges the clear rain, and the old flowers destroy another spring; Lonely now, Cao Fang Road is green and rainy every year; Apricot flowers are scattered in the clear rain, and how many flowers have opened on the branches of apricot trees; The south garden is full of light flocs, and it will be sunny and rainy for a while; Make it take a while to clear the rain.

? As can be seen from the above ancient poems, the phenomenon of "clear and clear, but unclear" in ancient times is still relatively common.

? Maybe someone will ask, isn't that that crops are often affected? Of course, the impact will be there, but it will not be too great. Because spring rain is as expensive as oil, it is often "clear rain". Even if the temperature drops, it will not be too severe, unless it is "chilly in spring".

? I sincerely look forward to this: sunny days will help the growth of seedlings, and rain will help the growth of seedlings in Grain Rain!