China's eastern and southern provinces are experiencing extreme heat waves with roasting temperatures and burning sunshine, but experts said the scorching weather may start to ease late this month.

A sizzling Shanghai saw temperatures soar to 40.4 C on Sunday — the highest so far this summer. The city has experienced maximum temperatures topping 40 C since the start of this month, with its meteorological center issuing the city's first red alert for high temperatures — the highest level — on Thursday.

"Based on our forecast, most of China's provinces and regions will see higher temperatures this month than in previous years," Jia Xiaolong, deputy director of the National Climate Center, told a recent news conference.

"The nation will experience two heat waves till mid-August and the scorchers will ease late this month."

He said that under the effects of a Western Pacific subtropical high and continental high, some eastern and southern provinces such as Fujian, plus areas in the northeast and northwest including the Inner Mongolia autonomous region, will see the highest daytime temperatures reach 35 to 38 C early this month.

Eastern provinces including Anhui, Jiangsu, Zhejiang and Jiangxi will be hit by continuous scorching temperatures until Wednesday, with daytime maximums of 39 to 42 C, he said.

Those eastern provinces have raised temperature alerts from orange to red in the past few days.

Several cities in Zhejiang have issued red alerts for high temperatures, and at 4:30 pm on Sunday, most of the province's cities recorded temperatures above 40 C.

Cities including Tonglu, Yiwu and Jinyun had their highest daytime temperatures ever, China Central Television reported on Monday.

"I'd like to live in the refrigerator. Just joking, but it's really hot in the daytime," said Chen Yan, 32, from Hangzhou, Zhejiang's capital city.

"I usually leave my apartment for work around 7:30 to 8 am, and I feel like I'm stepping into an oven. It's even worse outdoors around noon."

He said he would not normally allow his daughter to eat two ice creams a day, but has made an exception because of the sizzling weather.

Zhou Lixian, a forecaster from the China Meteorological Administration, told CCTV that the current heat wave in eastern provinces and Shanghai is the strongest and most intensive so far this year, and the scorchers will continue this week with highs close to or exceeding 40 C.

Zhang Jiancheng, deputy director of the National Climate Center, reminded members of the public to avoid outdoor activities at the hottest times of the day and to protect themselves from the sun.

He suggested people drink water containing salts or minerals if they feel uncomfortable after sweating too much, and also reminded the public not to stay in rooms with unreasonably low air conditioning temperatures for a long time or overindulge in cold drinks.