East China's Shanghai experienced its hottest day in history on Wednesday, with temperatures of 40.8 degrees Celsius breaking the record of 40.6 degrees Celsius set on July 26.

Wednesday marked the most sweltering point since the business hub's meteorological records began 140 years ago, according to the city's meteorological center.

Shanghai on Wednesday issued its fifth red alert this year for high temperatures.

So far, the city has had 33 days of high temperatures, including 19 days with temperatures of 37 degrees Celsius or above, and three days of temperatures higher than 40 degrees Celsius.

Weather forecasters said the hot weather will continue in Shanghai, with temperatures of about 40 degrees Celsius on Thursday and Friday.

"It's really hot. I am sweating all over and have drunk five or six bottles of water," said a mail carrier surnamed Zhang on a road in Shanghai.

"There are so few people on the streets in such a hot day. How can my beverages sell well?" said a saleswoman named Wang in a small shop in the metropolis.

Prolonged scorching weather has swept many parts of east and central China. Heatstroke has left at least 10 people dead in Shanghai. Central China's Hunan Province and southwestern Chongqing Municipality have each reported three deaths from the condition.

Chinese meteorologists have attributed the extremely hot weather to a number of factors, including strong, stable subtropical high pressure, the absence of typhoons and global warming.