China is set for the return of more heatwaves over the next 10 days, with temperatures set to start spiking in parts of the country on Saturday.
Some coastal cities are already on their highest alert level and inland regions warning of dam failure risks because of melting glaciers.
This Saturday is the day of the “big heat” in the Chinese Almanac based on the lunar calendar.
The hot spell was expected to be similar in scope as heatwaves from 5-17 July, but more regions could be hit by temperatures of 40C (104F) or higher, Fu Jiaolan, chief forecaster at the National Meteorological Centre, told state media.
Some cities in Zhejiang province, home to many factories and exporters, on Friday issued red alerts – the highest in a three-tier warning system – forecasting temperatures of at least 40C in the next 24 hours.
The load on the national power grid could reach a new high this summer as demand for air-conditioning by homes, offices and factories surges, with safe operation facing “severe tests”, the ministry of emergency management warned on Friday.
“For all of the factories in China and in Shanghai we have regulations that need to be followed,” said Leo Zhang, president of chemical product maker Sika China.
“Every year we do things to make the work more comfortable, for example giving workers ice-creams when it gets too hot.”
Zhejiang, as well as parts of Fujian, Guangdong, Hunan, Jiangxi and the city of Chongqing, also stood at risk of forest fires in the near term, the ministry said.
The western region of Xinjiang on Saturday warned of more flash floods and mudslides and risks to agriculture as heatwaves swept across the region.
Xinjiang’s latest heatwaves had been particularly long lasting and widespread, Chen Chunyan, chief expert at the Xinjiang Meteorological Observatory, told state media.
She noted the extreme weather in the south and east of the region – more than twice the size of France – had already lasted for about 10 days.
“Continued high temperature has accelerated glacial melting in mountainous areas and caused natural disasters such as flash floods, mudslides and landslides in many places,” Chen said.
The China Meteorological Administration said a day earlier that the glacial melting in Xinjiang posed a high risk of dam failure on a tributary of the Aksu River near China’s border with Kyrgyzstan.
Such heatwaves could also impact crops, especially cotton, Chen said. Xinjiang accounts for production of about 20% of the world’s cotton, a water-thirsty crop. By some estimates, 20,000 litres of water is needed to produce 1kg of cotton, enough for one T-shirt and a pair of jeans.
The heat in China this summer has been described as extreme. From 1 June to 20 July, the Yellow River and Yangtze River basins – major centres of industry and commerce – were hit by at least 10 high-temperature days more than the norm.
Heatwaves have also scorched other parts of east Asia, western Europe, north Africa and North America, sparking wildfires in many countries.
Scientists caution that climate change will only make heatwaves hotter and more frequent.
The highest-ever recorded temperature in China is a matter of debate. According to Chinese media, the hottest period in the past 300 years was in July 1743 during the Qing dynasty, with a French missionary in Beijing said to have recorded an all-time high of 44.4C.
In 2015, a local news portal reported 50.3C at a weather station near Ayding, a dry lake in Xinjiang’s Turpan Depression.
Temperatures in the oasis city of Turpan could reach 50C next week, the China Meteorological Administration said on Friday.