Why does the first frost frost?

1, the first frost does not mean "frost", but it means that the weather is getting colder and colder, and frost will appear as long as it is cold. The arrival of the first frost solar terms just means that it has entered the late autumn. With the frequent cold air, this is a phenomenon that the earth will be frozen or will produce the first frost. It is worth mentioning that there is no concept of "first frost" in meteorology. Meteorology calls the first frost in autumn "first frost" or "first frost" and the last frost in spring "late frost" or "final frost". The interval from the last frost to the first frost is a frost-free period. Because there is frost when it is frozen, "autumn frost" and "spring frost" are collectively called frost.

In addition, some people think that the first frost fell from the sky, but it is not. Instead, it comes from the ground. Frost, like dew, is formed by condensation of water vapor on the ground in cold weather. When the temperature is not too low, it condenses into dew. If the temperature is lower, it will condense into frost.

3. Because frost is formed by the condensation of water vapor in the air near the ground and objects on or near the ground, it will also flow with the air, and the coldest and heaviest air will flow to the lowest place, so low-lying places are more prone to frost than high-lying places, which is also the reason why some plants in low-lying places are particularly prone to frost. The ancients also found that frost was related to the weather. The agricultural proverb "Once it was sunny in first frost, it was sunny for a long time in first frost" means that there was frost in the morning and the weather was sunny for a short time; And if there is frost in three mornings, the sunny days will last longer. This makes sense and is still accurate today.