Residents in Shanghai and its nearby regions won't get a break from the extreme heat until next week, as power suppliers gear up for surges in electricity consumption for air conditioning.

On Wednesday, the city's meteorological department recorded a temperature of 38.6 C at about 2 pm in the city's Xujiahui area, the highest this summer.

The number of extremely hot days this month may even surpass July 1934, the hottest month in the city's history, when the mercury surged above 35 C for 23 days, said Wu Rui, chief meteorologist at Shanghai Meteorological Bureau.

In Hangzhou, the temperature topped 40.4 C on Wednesday, the highest on record since 1951, according to the city's meteorological bureau. It is the second consecutive day that the city's temperature has exceeded 39 C.

The large number of extremely hot days this month is closely related to the subtropical anticyclone in the western Pacific, which is stronger and closer to eastern China this summer, meteorologists said.

Due to its influence, a large area of eastern China was quickly shrouded in the extreme heat when the rainy season ended on June 30 this year. The anticyclone continues to grip Shanghai and its nearby regions this summer, leading to the large number of extremely hot days.

"The subtropical high pressure belt is very stable this year in the Yangtze River Delta. The rain belt in northern China remains strong, which results in the subtropical high pressure belt being unable to move northward," said Yang Jun, deputy director of Hangzhou meteorological bureau.

But residents can expect a relatively cool August, meteorologists said.

"It's unlikely there will be two continuous extremely hot months," Wu said.

Shanghai's meteorological department estimated a total of 30 days this summer when the mercury will climb above 35 C, and 18 such days had been recorded by Wednesday.

Along with the extreme heat comes a surge in power consumption.

According to Li Defu, a media official with Shanghai Municipal Electronic Power Company, the city's electricity consumption reached 28.02 million kW at 1:50 pm on Wednesday, a record high.

But the company is still capable of coping with the surge and the city's grid remained stable, he added.

The city's largest power generation capability was 31.23 million kW on Wednesday, combining power generated by local generators, electricity transferred from western China and power for spare use.

The Hangzhou branch of Zhejiang Electronic Power Company estimated that electricity use would reach 10.8 million kW in Hangzhou this summer, growing 9.5 percent year-on-year. But on Wednesday, the electricity use reached 11.31 million kW, setting a new record in the city's history.

The company said high energy-consuming businesses such as cement factories have been required to stop operations for at least 20 days starting from July 19 to ensure electricity supplies in the city will be sufficient when the peak season arrives.

To relieve the power crunch, authorities in Shanghai have switched off all floodlights, except those on the Bund, since Tuesday, when the mercury surged to 38.4 C.

Most of the city's floodlights, including those on the landmark Oriental Pearl Tower, will remain switched off on days when the temperature climbs above 38 C.

Only the Bund area is an exception, which reduces the impact of a shut-off on tourism. But officials said lights in the Bund area have been revamped for energy conservation.

"I support the city's effort to save energy by switching off floodlights on super-hot days," said resident Liu Xinyou. "No one likes to see power supplies fail on these days."

Contact the writers at wangzhenghua@chinadaily.com.cn

(China Daily 07/25/2013 page5)