Areas across China have been tested by extreme weather, including heat, drought and flooding, this summer.

After sweating through the hottest July on record, Shanghai upgraded its daily high-temperature alert from orange to red, the highest on the country's three-tiered color-coded heat alert system, at 10 a.m. on Tuesday, as the weather forecast showed a high of 40 degrees Celsius.

Tuesday also marked the fourth hot day in August for Shanghai, which saw a record-high temperature of 40.6 degrees Celsius on Friday.

The previous record was set in 1934, when a temperature of 40.2 degrees Celsius was recorded.

Shanghai's municipal government has requested that all companies and units ensure safe working conditions in the severe heat, especially for those working outdoors.

Power consumption exceeded 50 billion kwh in July in neighboring Jiangsu Province, the highest among all provinces, partly due to the wide use of air-conditioners.

Meanwhile, 326 rivers had been cut off, 65 reservoirs dried up and 1,100 others left with dead storage levels in central China's Hubei Province, dubbed "the land of a thousand lakes," as of Tuesday.

The current heat wave has swept 13 provincial-level areas across China, leaving about 5.95 million people and 1.72 million heads of livestock short of drinking water, according to a Monday report from the Ministry of Civil Affairs.

Of those affected, about 4.3 million people live in Guizhou and Hunan provinces, and the rest are in Hubei, Jiangxi and Zhejiang provinces and Chongqing Municipality.

The drought has caused direct economic losses of 12.1 billion yuan (1.98 billion U.S. dollars) and affected about 2.09 million hectares of farmland, including 350,000 hectares that have been left unharvestable.

Up north, however, flooding has become an issue.

Ten rounds of rainfall have battered north China's Shandong Province since the beginning of July.

The province received 328.1 mm of rainfall in July, a 50-year high.

From Thursday to Monday, heavy rains severely affected 399,000 people and destroyed 440 houses in Shandong.

In arid northwest China, Gansu Province received double the average annual precipitation recorded for the past 30 years in July.

"It is certain that there is a trend of increasing extreme weather events in summer," said Zhao Hongyan, an engineer with the Northwest China Climate Center.

Arid northwest China is more vulnerable to rainstorm-triggered landslides and torrential flooding, and people there have been warned to enhance their awareness of flood and waterlogging prevention, he added.

Twenty-four people died and one person was reported missing after rainstorm-triggered floods and flows of mud and rock hit Tianshui City in Gansu on July 25.

Four rounds of downpours swept Tianshui City in July, triggering floods, landslides and mud-rock flows in seven townships and affecting 1.22 million people.