At least 33 have died in the wake of rains that lashed central and south China. Hunan province has suffered $1 billion in direct losses.
Torrential rain lashed parts of central and south China on Monday, with floods damaging crops, forcing hundreds of thousands from their homes and killing at least 33. Meanwhile, the north wilted in a heat wave and drought-like conditions.
Water levels in more than 60 rivers in southern China have risen above warning levels, the flood control authority said.
At least 33 people are confirmed dead and 15 are reported missing as of Monday morning after heavy rain and flooding engulfed central and southern provinces including Hunan, Hubei, Anhui, Sichuan and Guizhou, China's civil affairs ministry said.
The annual rain season, which arrived in the second half of June, has hit southern Hunan province the most. Weather forecasters predict the relentless downpours could start to ease in coming days.
Xiangjiang, a major tributary of the Yangtze River, has exceeded its record flood level in the Hunan capital of Changsha. Floods in the city have swamped houses, uprooted trees, damaged cars and submerged roads.
More than 300,000 people have been evacuated across Hunan, which has lost 295,000 hectares of crops and seen more than 6,000 homes destroyed.
Across Hunan, the flooding has caused a total direct economic loss of 8.26 billion yuan ($1.22 billion), the provincial civil affairs office said.
Blackout in Guangxi
In Guangxi, 16 people have been confirmed dead and 10 are missing after a flood hit the southwestern region after a storm, the official Xinhua news agency cited authorities as saying.
Southern provinces produce some of China's major crops.
Guangxi is China's top sugarcane-growing region, while Hunan is its third-largest hog-farming province. Rice is grown south of the Yangtze.
China will take steps to ensure sugar reserves are safe during the rainy season, the Sugar Reserve Management Centre said.
China Southern Power Grid reported an extensive blackout in Guangxi. Electricity to half of the affected area was restored by Monday morning.
The state post bureau warned of courier delays in parts of the central, southern and southwestern provinces.
By contrast, stifling heat has settled over Beijing, Hebei, Henan and other northern provinces since last week, with temperatures forecast to reach 40 degrees Celsius in some areas on Monday, the meteorological bureau said.
Cities in Shaanxi province issued alerts, saying temperatures could exceed 35 degrees Celsius in the next three days.
Many residents in the province have ordered food to be delivered rather than cook at home in the heat, a Shaanxi newspaper reported.
In Beijing, many residents stayed indoors over the weekend due to the heat.
In the Inner Mongolia region, more than 200 firefighters are battling a grassland fire that has crossed over to northern China from Mongolia, Xinhua reported.
The blaze has spread quickly in the heat, dry conditions and strong winds.
The heat wave is expected to ease by mid-week.