Cherish the time! Big data tells you that autumn is getting shorter in these places

Entering the Autumnal Equinox, most of northern my country has entered a cool autumn, but the south of the Yangtze River and southern China are still in a hot summer. Many southern friends complain that "we don't have spring and autumn, we only have winter and summer", "Spring and Autumn only existed during the Warring States Period", "Guangdong doesn't deserve autumn"... So, has the autumn in southern my country really shrunk? China Weather Network has specially counted the autumn big data to see whose autumn came late and whose autumn became shorter?

The time of autumn in the north and south is very different, with a difference of more than 100 days

In meteorology, autumn is defined as the day when the average daily temperature or sliding mean temperature is less than 22°C and greater than or equal to 10°C. When the annual sliding mean temperature sequence is less than 22°C for five consecutive days, the first day in the corresponding annual temperature sequence that is less than 22°C is the start of autumn.

my country has a vast territory, and the time of autumn in the north and south is very different. In parts of central and southern Tibet, southwestern Sichuan, and high-altitude mountainous areas of Yunnan, autumn is generally considered to have arrived in June; in July, central and northern Heilongjiang, central and eastern Inner Mongolia, northern Xinjiang, the eastern Qinghai-Tibet Plateau, and the western Sichuan Plateau also start the autumn process early.

In August, most of Northeast China, Inner Mongolia, most of Northwest China, central and northern Shanxi, central and western Guizhou, central Sichuan and other places also entered the autumn territory. In September, the autumn front arrived in central Zhejiang, northern Jiangxi, central Hunan and northern Guangxi, and in October it reached the southern coastal areas of South China; Guangdong and southern coastal areas of Guangxi, Hainan Island, Taiwan Island and other places will not welcome autumn until November.

Among the big cities, Hohhot enters autumn the earliest, generally entering the threshold of autumn on August 12th. Haikou has to wait until November 26th, making it the last big city to experience the "autumn coolness". The autumn seasons in the south and the north are 106 days apart.

Autumn is short, with the average duration in North China and Northeast China being around 50 days.

Between the hot and long summer and the cold and long winter, the cool and beautiful autumn is extremely precious, but beauty is always short-lived. The autumn in various parts of my country is generally not long, and the southwest region is relatively long, about 70 to 80 days. Except for Kunming, which is not included in the inventory because spring and autumn are connected, Guiyang, Chengdu, and Chongqing are far ahead in the length of autumn. Guiyang has the longest autumn, which is 79 days. It can be said that it has the "longest autumn".

The shortest autumn season is in Northeast China and North China, with most being around 50 days. In Beijing, my friends even joked, "Take off your summer clothes and put on your winter clothes directly." Windbreakers are the least practical outfit.

It's getting later and later. Autumn has been delayed for more than 10 days in Zhengzhou, Shenzhen and other places.

China Weather Network found through an inventory of meteorological big data that autumn has been delayed in many parts of my country since 1991, and generally speaking, it is more obvious in the eastern region than in the western region. Comparing the average autumn dates from 1991 to 2020, the autumn in Zhengzhou, Ningbo, Shenzhen and other places has been delayed the most, by more than 10 days. The autumn in Nanjing, Hefei, Hangzhou, Nanchang, Xiamen, Fuzhou, Qingdao, Lanzhou, Yinchuan, Urumqi and other cities has also been delayed by 5 to 9 days compared with before.

The paper “The Impact of Sudden Changes in Temperature on the Start Dates of the Four Seasons in my country” also shows that, on average, spring and summer have started earlier, while autumn has started later, since the 1990s. [1]

The delay in the onset of autumn is closely related to global warming. Wang Weiyue, a meteorological analyst at China Weather Network, said that under the background of global warming, the gradual increase in temperatures in various regions has become an indisputable fact, affecting agricultural production, social economy and people's daily lives. Rising temperatures will inevitably affect the climate season measured by average temperature.

The autumn season in this place is getting shorter and shorter. It has shrunk by 12 days.

Autumn is not only coming later, but also gradually shortening in length. Many scientists have studied seasonal changes in my country and found that the onset of autumn and winter in many places has been delayed, and the lengths of winter, spring and autumn have all shortened; from a regional perspective, the changes are more obvious in the north than in the south, and more obvious in the east than in the west.

China Weather Network sorted out meteorological data from the past three decades and found that the changes in autumn in many parts of my country since 1991 are consistent with the research results. Among the big cities, Changsha, Ningbo, Hangzhou, Shanghai, Zhengzhou, Yinchuan and other places have obviously "shrunk" in autumn, with Ningbo being the largest, with autumn shortened by 12 days from the 1990s to the present, and Yinchuan, Hangzhou and Changsha also shortened by 7 to 9 days.

Whether it comes late or becomes shorter, it reminds us that the "most poetic autumn" is a short and precious existence. Friends who have already felt the autumn, quickly embrace the autumn and enjoy the beauty of the sky and clouds. (Planning/Zhang Hui Data Support/Wang Weiyue Hu Xiao Design/Ren Chengying Zhang Li)

[1] Yu Zhenyan, Fan Guangzhou, Hua Wei, et al. Impact of sudden temperature change on the start date of the four seasons in my country [J]. Meteorology, 2010, 36(11): 32-37.

Note: The major cities listed in the article include: Beijing, Shanghai, Guangzhou, Shenzhen, Xiamen, Ningbo, Haikou, Nanning, Fuzhou, Chengdu, Chongqing, Nanchang, Changsha, Wuhan, Hefei, Nanjing, Hangzhou, Shanghai, Jinan, Zhengzhou, Shijiazhuang, Tianjin, Shenyang, Changchun, Harbin, Hohhot, Taiyuan, Xi'an, Yinchuan, Lanzhou, Urumqi, Qingdao, and Dalian.

Kunming, Lhasa, Xining and other areas without summer are not included in this autumn inventory.