When did it start to frost in the south?

In the early morning of cold season, grass leaves and clods are often covered with a layer of frost crystals. They shine in the rising sun and melt when the sun rises. People often

Call this phenomenon "frosting". Looking through the calendar, every year from 10, there is always the solar term "first frost". We have seen snow and rain, but no one has seen frost. Actually, frost didn't fall from the sky.

But in the air near the ground. Frost is a kind of white ice crystal, which mostly forms at night. In a few cases, it can also begin to form before sunset when the sun is tilted. Usually, the frost will melt soon after sunrise.

But when the weather is cold or in a cool place, the frost will last all day. In the cold season, frost usually forms on sunny, breezy or calm nights.

Related content explanation:

The first frost, the eighteenth of the twenty-four solar terms, is the last solar term in autumn, marking the transition from autumn to winter. As the saying goes, "the first frost kills a hundred herbs." After the first frost, the plants gradually lost their vitality and the land was desolate.

In ancient times, the first frost was divided into three stages: one stage was when jackals sacrificed animals; Second, the vegetation is yellow; Three stings are salty. This means that after the first frost, jackals and other animals began to store food for winter; The vegetation is yellow and the leaves are falling; The hibernating mantis lowered its head and prepared to spend the winter in the cave.

Climatic characteristics of the first frost;

1, southwest, etc. The rainy season has begun.

From 1 1, the autumn rain in West China basically ended and entered a period of little rain in a year. Some southwest areas are located in plateaus, some in basins and hills, and the weather will naturally be different. But on the whole, the average temperature at this time has not reached the standard of winter.

It is not as humid as summer, nor as dry as spring, and the temperature difference between morning and evening is not as obvious as spring. It should be said that it is a more comfortable time of the year. Sichuan basin, during this period, the climate is mild, and the fields are green and orange.

2. Northwest, Northeast and other places: weather characteristics in early winter.

From the late period of 10 to the early period of10, the northwest and northeast regions of China have already presented the scene of cold wind and falling leaves in early winter. Cold air is not only a frequent visitor, but also the first guest received in these areas.

Generally, cold air is either dry wind or rain and snow, and cooling is a specialty that every batch of cold air should send. Since China has entered a warmer period since the mid-1980s, extremely strong cold air is rare.