Every year Autumn Begins falls on the 7th or 8th of August, when the sun reaches the longitude of 135°. Autumn Begins (Liqiu in Chinese) is one of the 24 solar terms which reflects the withdrawal of summer and the beginning of autumn.

How to Calculate Date of Start of Autumn?

Formula: [Y*D+C]-L

Note: Y refers to the last two numbers of a year, such as 10 in 2010, 08 in 2008

D=0.2422

L=the number of leap years

21st century C=7.5 20th century C=8.35

Example: The date of Start of Autumn in 2088=[88x0.2422+7.5]-[88/4]=28-22=6, so Start of Autumn falls on August 6th.

Exceptions: 2002, add one to the calculated result

What is The Origin of the Autumn Begins?

According to historical records, the Start of Autumn not only foretells the end of the scorching summer, but also indicates the fruitful season is approaching, a time when early rice is gathered and late rice is transplanted. It is the time that autumn crops come into their crucial growing stage. In ancient China, people emphasized a lot on the Start of Autumn since they regarded it as the significant point when summer turned into autumn. As recorded, in the Song Dynasty (960-1279), potted Chinese phoenix trees would be moved into palace halls on the day of the Start of Autumn. At the exact time of the Start of Autumn, the official would shout “autumn is coming!” Then along with the falling of several phoenix tree leaves, autumn began.

In ancient times, the Start of Autumn was divided into three phases: “In the fist phase comes the cool wind”. After the Start of Autumn, northern winds start to prevail in many places of China, bringing coolness to the land.

“In the second phase fall the white dews”. During this period of time, it is still very hot in daytime, but pretty cool in the evening. The difference in temperature between the day and the night means dew will form on the surface of outdoor plants in the morning.

“In the third phase cry the cicadas”. With sufficient food and convenient temperature, cicadas cry pleasantly on trees, as if they are informing us the departure of summer. Start of Autumn is all together 15 days long, 5 days in each phase. The Start of Autumn is when the weather starts to become cool.

When Start of Autumn begins, many places in China are still very hot. Although it may remain hot for some time even after the Start of Autumn, the weather tends to cool down. The difference in temperature between the day and the night becomes more and more obvious. However, due to the diversity of climate throughout the country, the true starting time of autumn differs.

In reality, there are many ways to mark the beginning of autumn: according to solar terms, the Start of Autumn symbolizes the beginning of autumn; in astronomy, it is the Autumn Equinox which is figured out by the orbit in which the Earth revolves around the Sun; given climatic statistical data, autumn begins from September and judging from the daily average temperature, the first day of the successive five days in which the daily average temperature is between 10℃ and 22℃ is considered the initial day of autumn.

As mentioned before, owing to the geographical difference between the northern and southern China, not all the places in China enter autumn at the same time. In mid August, Heilongjiang Province and north Xinjiang Province meet autumn earlier than any other parts of China. Normally, autumn will arrive in northern China in early September and in the southwest part and Qinhuai area in mid September. In October, it reaches the Jiangnan and then Lingnan areas. In mid November autumn moves to Leizhou Peninsula and north Hainan Island at a leisurely pace, and when autumn eventually comes to Sanya City, it is almost New Year’s Day.