Residents flood to the beach amid the heat wave on June 1, 2023 in Shenzhen, South China's Guangdong Province. Photo: VCG

A total of 578 national-level meteorological observatories in the southern China have recorded new temperature highs for the same period in history, including 25 recording highest temperatures as of Wednesday, since the latest heat wave that began on May 26. 

Multiple provinces including East China's Zhejiang, Fujian and Jiangxi, Central China's Hunan, and South China's Guangdong and Guangxi Zhuang Autonomous Region have experienced high temperatures of 35 C or above.

Southwest China's Sichuan and Guangdong have issued their first high temperature red alerts for this year, according to media reports. 

The most intensive period of high temperatures was between May 29 and 31. The meteorological observatory in Qiaojia county in Southwest China's Yunnan Province reached 43 C on May 29, the highest temperature recorded for this heat wave, the Global Times learned from the National Meteorological Center (NMC) on Thursday. 

Chen Tao, chief weather forecaster at the NMC, pointed out that the continuous heat in southern regions since May 26 has had a wider range of influence and more intensive power compared with the same period in history. 

The sultry feeling is apparent in southern China with high relative humidity, whereas the high temperature days in Yunnan and the southern parts of Sichuan are dry and hot. 

Chen attributed this heat wave to the main weather systems of super typhoon Mawar and the Western Pacific subtropical high. 

Local high temperatures are also influenced by special geographic factors such as river valleys and mountain valleys. For example, Qiaojia county in Yunnan has many mountain valleys. Its closed terrain is not conducive to the dissipation of heat. 

The NMC predicted that in the next three days, there will be continuing "high heat" in multiple places including the majority parts of South China, the southern part of Guizhou, the northern and southern parts of Yunnan, and the southern part of Sichuan. Temperatures may reach 37-39 C in some places and even exceed 40 C. 

With Mawar turning northeastward starting from June 1, the subtropical high pressure will gradually weaken and retreat southward, resulting in a gradual decrease in high temperatures in the southern parts of China. 

It is expected that this round of high temperatures will last until June 4 to 5. In South China, it may last until June 6 and thereafter. 

The World Meteorological Organization (WMO) recently released an update saying the likelihood of El Nino developing later this year is increasing. The El Nino climate pattern in the Pacific Ocean this year would have the opposite impacts on weather and climate patterns in many regions of the world to the long-running La Nina, which has ended, with dangerously high temperatures and extreme weather events expected. 

El Nino and La Nina are natural phenomena that the WMO describes as "major drivers of the Earth's climate system." 

After a three-year La Nina spell, which is associated with ocean cooling, the world faces an 80 percent chance of an El Nino event developing between July and September this year, according to the WMO.