A cold front will sweep central and east China, including Shanghai, over the next three days and bring rains and temperature drop, Monday's weather forecast said.
Temperatures will drop by four to eight degrees Celsius in most parts of those regions, the China Meteorological Administration (CMA) said.
Temperatures in north China will also see a withdraw, trying to hold off the coming of summer, it said.
Expo visitors in Shanghai may as well get umbrellas ready Tuesday and Wednesday, since thunder shower will hit the city and bring temperature drop by 2 to 4 degrees Celsius.
Light rain will hit Yushu, in northwest China's Qinghai Province Monday. And for the next two days, cloudy weather will dominate the area.
The southern part of Shaanxi, eastern areas of Sichuan basin, southeastern part of China's Northeast region, most parts of the Huaihe River valley and areas to the south of the Yangtze River will see big rainstorm in the coming three days.
Heavy rains will hit north of Chongqing, northeast of Guizhou Province and central and southern part of Jiangxi Province. The rainfall is ranging from 100 to 130 millimeters.
The majority parts of Xinjiang Uygur Autonomous Region, Inner Mongolia, west Gansu Province, north China and northeast China would see wind of 4 to 6 degrees.
The CMA also reminds people nationwide to take precautions against allergies caused by willow catkins and pollen flying in the air recently.