Four government departments issued a notice on Tuesday urging action to protect crops, calling for "every unit of water to be used carefully" through methods including staggered irrigation and cloud seeding, which aims to induce rain.
"The rapid development of drought superimposed with high temperatures and heat damage has caused a severe threat to autumn crop production," the statement said.
The warning comes as multiple Chinese provinces announce power cuts to cope with a surge in demand, driven partly by people cranking up the air conditioning to cope with temperatures as high as 45 degrees Celsius (113 degrees Fahrenheit).
The megacities of Shanghai and Chongqing have cut outdoor decorative lighting, while authorities in southwestern Sichuan province have imposed industrial power cuts as water levels drop at key hydroelectric plants.
More than 1,500 people in the area surrounding Chongqing were evacuated on Monday after hot and dry conditions sparked multiple wildfires, according to state news agency Xinhua.
The national meteorological service renewed its warnings for drought and high temperatures on Tuesday, calling for 11 provincial governments to "activate" emergency responses.