as the saying goes, "frost begins to fall". In the frost season, the Yellow River Basin in China has begun to fall, but the initial frost time is different everywhere. Generally, it shows a trend of gradually delaying from north to South and from high mountain to plain. So what is the temperature of frost and how many degrees will frost fall? Today's old yellow calendar will introduce you.
what is the temperature before the frost season? If strong cold air goes south, the ground surface temperature drops to 0 ℃ or lower, and the water vapor in the air near the ground reaches saturation, it will directly condense on the ground or near the ground objects to form fine ice crystals. How much temperatureand
can cause Frost: the formation conditions of frost are related to weather conditions and the properties of the attached objects. The temperature of the object surface is very low, but the air temperature near the object surface is relatively high, so there is a temperature difference between the air and the object surface. If the temperature difference between the object surface and the air is mainly caused by the radiation cooling of the object surface, the air will cool when the warmer air contacts the cooler object surface, When the water vapor is supersaturated, the excess water vapor will precipitate.
if the temperature is below 0 ° C, the excess water vapor condenses into ice crystals on the object surface, which is frost.and
the time of first frost varies in different regions. In the southern region of south latitude in China, the average temperature is mostly about 16 ℃. At this time, there are three solar terms before the date of first frost. In the southern valley of South China, frost can only be seen in the middle of winter. Of course, even in places with the same latitude, due to different altitudes and terrain, the temperature and humidity of the air near the stratum are different, and the initial frost period and frost days will be different.and
in addition to the areas with frost all year round, the earliest frost in China is in the north of Daxinganling, which is generally visible at the end of August; The first frost mostly occurs in September in most of Northeast China, Inner Mongolia and Northern Xinjiang; At the beginning of October, frost has appeared in Shenyang, Chengde, Yulin, Changdu Lhasa line; In early November, frost can be seen from Shandong Peninsula, Zhengzhou, Xi'an to Northwest Yunnan; Frost does not begin to appear until early December in areas around 30 ° n in eastern China, Hanshui and 20 ° n in Yunnan Province; It was early January after the new year when the frost appeared in Xiamen, Guangzhou, Baise and Simao.https://www.dailyq-a.com/Culture/27295.html
This article only represents the author's point of view, not the standpoint of this station.
This article is authorized by the author and cannot be reproduced without permission.