Chinese officials said more provinces of the rain-soaked country had been flooded and warned of imminent geological disasters such as landslides.
The Central Meteorological Station said more torrential rain, thundershowers and hurricanes were forecast for parts of Henan, Anhui and Jiangsu provinces.
The torrential rain is expected to make flood control work increasingly difficult in the worst affected province of Anhui, the officials said.
The Huai river is flowing dangerously high and already more than one million people have been marooned by its flood waters.
Another 380,000 people have been forced to move to higher grounds.
The State Flood Control and Drought Relief headquarters have set up seven flood diversion areas to hold 1.4 billion cubic meters of water in a desperate attempt to reduce the water level in Huai, the China daily said.
Thirteen people have died on being swept away by flood waters. Another five were killed by landslides triggered by the heavy rains.
In Xian, the capital of Shaanxi province in the country’s northwest, three people were killed on Monday in a sudden thunderstorm.
A large quantity of relief goods and a 5000-strong emergency task force have been sent to the affected areas.
The Chinese Minister of Water Resources meanwhile has warned that a third of the country’s reservoirs are threatened by floods, despite $1.35 million spent in recent years to maintain them.