Nanjing’s weather, as many a Chinese will tell you, is known nationwide as a “furnace”. It’s a formidable beast, indeed, but it’s also one that has changed beyond all recognition over the past few decades, a point that 2020 has proved only too well.
Traditionally, China has three cities known as furnaces (三大火炉); the now infamous Wuhan, mountainous Chongqing and our very own Southern Capital. Some will content that Changsha and/or Nanchang also be counted as furnaces, and then there are those who vote too for Shanghai and Hangzhou.
In reality, this is little more than uninformed public opinion. Meteorologists beg to differ and they have the data to prove it.
Technically a subtropical monsoon climate, Nanjing is more than just hot; it’s wet too. With an average humidity level throughout the year of 75 percent, Nanjing is one of China’s most humid cities.
And it’s also a metropolis which has unique weather patterns. Writing for Career China in June of 2018, Thomas J. Davidson put Nanjing top of his list of China destinations, and of the weather he says, “It also has four distinct seasons which give the city four different atmospheres throughout the year, and it remains strikingly beautiful in each of them”.
It hasn’t always been that way. But it has always been unique. Long, long ago, Nanjing’s skies were grey ad nauseam and the seasons sparse, as any old Nanjing hand will testify.
Helmut Güsten, General Manager of Emz-Hanauer (Nanjing), says, “Spring was only a few days short. Autumn used to be a bit longer and nice, named Golden Weeks.
“Compared with 15 years ago, the actual weather is less predictable. Saturday 25th [July] in the morning saw a fresh 22 degrees centigrade. Unthinkable a decade ago. Apart from this year, the rainy season did not come as scheduled any more. In the early 2000’s, the rain started in June like clockwork”, said the German.
This year, however, has been altogether different for many reasons, and the weather is one of them. In 2020, China has suffered its worst flooding in decades. Estimates put the economic damage this year at US $12.3 billion, with some 37 million people along the Yangtze River Basin affected.
As to the cause, Song Lianchun, a meteorologist at China’s National Climate Centre, says global warming was a contributing factor to the severity of this year’s floods.
On a local level, this summer has been remarkable, agrees Kenny Lim Kam Sian, a PhD student majoring in Meteorology at the School of Atmospheric Science in Nanjing University of Information Science and Technology in Jiangbei New Area.
Speaking with The Nanjinger, he said, “Talking about this year’s summer season, it is very different as compared to previous years. Usually when summer is in, one will not expect any retreat from the suffocating humid air until September. However, this year’s summer came in very late. It was still cool in June, with unusual occurrence of several ‘cold spells’ in May and June”.
It’s not only students who have taken an interest in this year’s unusual weather. On 20 July, the China Meteorological Administration-Nanjing University Joint Laboratory for Climate Prediction Research hosted the “2020 Symposium on the Causes of Abnormal Precipitation”. Joining experts and scholars from the National Climate Centre, the Central Meteorological Observatory, Nanjing University and Nanjing University of Information Technology, were scientists and technicians from provincial meteorological bureaus, together with Ding Yihui, an academic from the Chinese Academy of Engineering. Ding said, “The early arrival of the strong front this year is the direct reason for the abnormally high rainfall during the peak flood season in the middle and lower reaches of the Yangtze River”.
According to Ding, the onset of the South China Sea summer monsoon in 2020 came early, with a northerly west Pacific subtropical high in early to mid June, bringing about an early start to an extended flood season for the middle and lower reaches of the Yangtze River.
Ding also pointed to a weak El Niño event that began in the autumn of 2019, when at the same time, the sea temperature in the North Indian Ocean was unusually warm, resulting in a significantly stronger subtropical high. This facilitated the transport of water vapour from the Indian Ocean to our region, while the resulting convergence of cold and warm air in the middle and lower reaches of the Yangtze caused the significantly higher than usual rainfall.
Back in Jiangbei New Area, Lim Kam Sian, who is from Mauritius, speaks to our city’s at times bizarre weather. “Nanjing City is known to have ‘capricious’ weather. According to climate averages, the hottest and wettest month in Nanjing is July. January is the coldest month and March is the windiest month”, he said. “Over the last nearly 10 years which I have spent in Nanjing, I can say for sure that the weather from year to year is very different”, he said.
While there have been, and always will be, extremes, Nanjing is also now enjoying weather conditions shared with many other once-polluted cities in China; blue skies and fluffy white clouds.
Co-Founder of Skyways Bakery, Patrick Hecklemann, is a German expat who has lived in Nanjing since 1993. “Several factors have more or less changed the weather to what it is now. Even this summer is very different”, he told The Nanjinger. “The pollution has tremendously improved and therefore we got to see a blue sky. Each year I find the skyline is better; higher and higher.”
Hecklemann also subscribes to the idea that Nanjing previously had virtually only two seasons and that recently there has been a profound shift away from such an odd climatic scenario. “For the past few years I experienced something like seasons in Nanjing, not cold, hot, cold. Spring, summer, fall and winter, however. Which is nice”, he said.
As the future unfolds, while we can be fairly sure that Nanjing will continue to be the aforementioned furnace, the city is blessedly now joined by a freezer, a cool box and a wind tunnel.
