Wang Enda knows his harvest this year will be meager.

The 58-year-old farmer in Haohuahong, a village in Guizhou province, sowed tens of thousands of corn seeds on his hectare of land in spring, but only a third of them sprouted due to the severe drought.

Water is rationed in Chang'an township, Hunan province, on Monday, as severe drought has caused water shortages for 1 million residents in the province.Guo Liliang / For China Daily

What is worse is that all his hot peppers and grapes, which were supposed to bring him handsome returns, withered amid the drought that is sweeping through at least nine provinces and regions.

"I'm not looking forward to the harvest," Wang said with a sigh, adding that his crop may be reduced by almost 70 percent.

Millions of farmers in the south of the country are struggling with the dry spell.

The China Meteorological Administration issued a national second-level heat alert on Tuesday, the highest alert in the country's history. The alert system has four levels.

The administration said temperatures in southern China will surpass 35 C from Tuesday to Aug 8, with some places expected to see the mercury hit record highs.

The searing heat wave has killed several people since the end of June and forecasters suggested people avoid extended outdoor activities.

Minhang District Hospital in Shanghai treated four people suffering severe heat-related illnesses in the past week, with two dying of severe heat stroke.

A 36-year-old construction worker and an 84-year-old man were also found dead due to the extreme heat in Changsha, the provincial capital of Hunan, on Sunday and Monday. Since July 1, local emergency and rescue centers have received more than 200 emergency calls reporting heat-related illnesses.

Tian Zheng, a doctor at a hospital under Hunan University of Chinese Medicine, suggested people drink more water and not set air conditioners at too low a temperature.

Yao Rong, a weather forecaster in Hunan, said temperatures may reach 41 C this week.

About 653,000 hectares of farmland had been affected by the drought in Hunan as of Sunday. One million people were short of drinking water.

The provincial government said the dry spell may continue for the next two months.

Yao, the weather forecaster, said efforts to induce rainfall, such as seeding clouds, have been made.

In Hangzhou, the capital of Zhejiang province, the summer heat has boosted power consumption.

On Tuesday, the city's electricity power distribution committee raised the measure of electricity usage to level F, the highest level.

Yang Yong, an official with the Hangzhou branch of the Zhejiang Electronic Power Company, said, "Scenic lighting will be turned off, and high electricity-consuming factories are required to stop production for at least three days a week."

Shopping malls, exhibition centers, restaurants, schools and buildings for officials are not allowed to set air conditioner temperatures lower than 26 C.

"Those who seriously violate the rules will face an electricity supply cutoff," Yang said.

Yan Yiqi in Hangzhou and Wen Xinzheng in Changsha contributed to this story.