By Ryan Woo
BEIJING (Reuters) -Beijing topped 40 degrees Celsius (104F) on Saturday for a record third day as the Chinese capital sweltered in extreme heat, while uncommonly high temperatures for June grilled an area the size of California in northern China.
At 1:51 p.m. (0551 GMT), the temperature measured by Beijing's benchmark weather station in its southern suburbs briefly soared above 40C.
Until Saturday, the city of nearly 22 million people had never logged three straight days above 40C since setting up the southern observatory in 1951.
Aside from Beijing, parts of nearby Hebei, Henan, Shandong, Inner Mongolia and Tianjin either raised or kept their hot weather alert at "red", the highest in China's four-tier warning system.
A red alert signifies the temperature could exceed 40C within 24 hours.
As of 1:13 p.m., an area of 450,000 square km (174,000 square miles) had recorded temperatures over 37C, according to local media.
"Last year's heatwave gives some sense of the risks to China's food supply and the potential impact on prices," Capital Economics wrote in a note on Friday.
"Another drought would hurt crop yields while livestock are vulnerable to high temperatures."
On Saturday, state media reported ground surface temperatures in excess of 70C in parts of Shandong - China's most populous province after Guangdong, and a key grower of grain.
The heatwaves, the second round in about 10 days, were caused by warm air masses associated with high pressure ridges in the atmosphere. The effect was amplified by thin cloud cover and long daylight hours around the summer solstice, according to Chinese meteorologists.
In Beijing between 1990 and 2020, the average number of days with temperatures of 35C or more was 10.6, the official Beijing Daily reported, citing official data.
June is not yet over and that number has already been beaten, the newspaper said, after temperatures in Beijing surpassed 35C for the 11th day this year on Saturday.
On Friday, Beijing baked in temperatures as high as 40.3C, after sizzling at 41.1C on Thursday, the second-hottest day recorded by the Chinese capital in modern times.
Beijing's all-time high of 41.9C was recorded on July 24, 1999.
The heat waves in northern China are expected to abate by Monday before regaining strengthen later in the week.