How long will it be hot after the cold dew?

The cold dew solar term begins at the end of the first ten days of 10 and ends at the end of 10. The direct point of the sun continued to move southward in the southern hemisphere, and the angle of sunlight in the northern hemisphere began to tilt obviously. The solar heat received by the ground is obviously less than that in summer, and the influence of cold air can sometimes extend to South China.

Literally, the "cold" of cold dew is cold, and "dew" represents the phenomenon that water vapor in the near-surface layer condenses into dew. However, from the meteorological point of view, the cold dew solar terms are the same as the white dew and the first frost, and the significance of its heat change is more obvious than its humidity change It should be said that it more embodies a process of temperature change and seasonal change.

During the cold dew period, the temperature difference between the north and the south is large, and some areas in the northeast and northwest can drop to 0℃, which makes them feel cold, while the temperature in many cities in the south is still above 25℃, which is a comfortable temperature. But the cold dew period is usually not hot, but many cities will feel the cold weather.

Climatic characteristics of cold dew

During the cold dew, the weather and climate have the following characteristics:

The temperature dropped rapidly.

The sudden drop in temperature is a feature of the cold dew solar terms. It is common for the temperature to drop by 8℃ and 10℃ after the autumn rain brought by a strong cold air. However, most stormy weather does not last long (except West China). Controlled by cold and high pressure, it is warm during the day, cool at night and crisp in autumn during the day.

The average temperature distribution varies greatly.

From June 5th to 10, the regional difference of the average temperature distribution in China is obvious. The average temperature in most parts of South China is above 22℃, and it is even higher in Hainan, which is above 25℃, and it has not yet come out of summer. Jianghuai and Jiangnan are generally between 15℃ and 20℃, and the southeast, North China and Huanghuai are between 8- 16℃. At this time, the average temperature in parts of the northwest and north-central northeast has reached below 8℃. The average temperature in some plateau areas of Qinghai Province is even lower than 0℃.

South temperature of cold dew

In the year of cold dew, the rainfall in South China is also decreasing day by day. The western part of South China is about 20 mm, and the eastern part is generally about 30 to 40 mm. The frequent rainfall around the clock has affected the emergence of "Sanqiu" and has become a disastrous weather in most parts of South China. The climatic characteristics associated with the rain in Mao Mao are: high humidity, more clouds, less sunshine and more cloudy days, and the number of foggy days has obviously increased since then. However, whether the autumn rain seriously affects the progress and quality of "Sanqiu" directly. To this end, on the one hand, we should use the weather forecast to harvest and sow in sunny days; On the other hand, according to local conditions, we should take various effective farming measures such as deep ditch and high compartment to reduce wet damage and improve sowing quality. In the plateau area, before and after the cold dew is one of the most serious seasons of snow damage. Snow jams traffic and harms animal husbandry production, so we should pay attention to prevention.

The southern rice areas should also pay attention to prevent the harm of "cold dew wind". North China should hurry to sow wheat. At this time, in case of drought and little rain, we should try our best to accumulate soil moisture, grab soil moisture for sowing, and ensure that sowing is completed before and after the first frost. We must not passively wait for rain to lead to planting early crops and late wheat. Before and after the cold dew is the suitable sowing date for direct seeding rape in the Yangtze River basin, and the variety arrangement should be to sow cabbage varieties first and then cabbage varieties. Those who sow green manure in the south of Huaihe River should be cleaned up, and those who have emerged should be cleaned and drained to prevent waterlogging. The tuber swelling of sweet potato in North China Plain has gradually stopped, and the probability that the morning temperature is lower than 10℃ or lower is gradually increasing. According to the weather conditions, we should pay close attention to harvesting and strive to finish it before the first frost, otherwise potato tubers will "harden their hearts" because they are frozen underground for too long, reducing the value of eating, feeding and industrial utilization, and cannot be stored or used as seeds.

Cold dew northern temperature

After the cold dew, the cold air in the north has a certain influence, and most parts of China are controlled by cold high pressure, and the rainy season is over. The weather is often warm during the day and cool at night, with clear skies and Wan Li, which is very beneficial to the autumn harvest. Thunderstorms have disappeared in most parts of Chinese mainland, and thunder can be heard only in parts of Yunnan, Sichuan and Guizhou.