Cold Dew begins at the end of the first ten days of October, and ends in the last ten days. The direct point of the sun shines on the southern hemisphere and continues to move southward, and the angle of the sun’s rays gradually tilts. The solar heat received on the ground decreases significantly, and the cold air spreads over a greater and greater area, even reaching South China. An old saying in Guangdong goes, “You must find a bridge on the third day (after the Cold Dew)”. This means that the weather is turning cold, people cannot cross the river or go to the fields with bare feet. It can be seen that during Cold Dew, people can feel the changes of the weather. People in more and more areas use the word “cold” when referring to the weather.

These are some weather features of Cold Dew:

Temperature drops quickly:

A precipitous drop in temperature is a feature of Cold Dew. After the autumn wind and rain brought by a strong cold air, it is very common for the temperature to drop 8 or 10℃. The rainy or windy weather, however, will not last for long (except in West China). Because of the cold high pressure, the day will be warm and the night cold. Clear, crisp days are very common in autumn.

The average temperatures are much different in different areas:

In October, the difference between the average temperatures in different areas is significant. In most areas of South China, the average temperature is more than 22℃. It is still summer in Hainan province, with an average temperature of more than 25℃. The temperature is 15℃ to 20℃ in the areas around the Yangze river, between Huai river and the south area of Yangze river, 8 to16℃ in the southern area of Northeast, North China and areas between the Yellow river and Huai river, while below 8℃ in the middle and north part of northeast area. The average temperature is even below 0℃ in the plateau area in Qinghai province.