It will be damp and cold this week and it will likely rain today, the Shanghai Meteorological Bureau said.
The temperature was forecast to be between 6 and 8 degrees Celsius today. The high this week will top out at 10 degrees while the low will dip to 3 degrees on Thursday as a cold front arrives, the bureau said.
The rain today will likely be heaviest in southern areas of the city.
Weather forecasters also said there will likely be strong winds this afternoon and that the rain could continue until tomorrow.
The air quality is predicted to be good early this week with the AQI between 60 and 100 due to the rain and wind brought from the southwest.
Yesterday, the AQI was 108, or lightly polluted.
The PM2.5 density at 3pm yesterday was 87 milligrams per cubic meter, above the national standard of 75.
Nationwide, the National Meteorological Center yesterday issued a blue alert as heavy rainfall in southwestern and southern China moved eastward.
Rainstorms were also forecast to batter the southern parts of Yunnan Province, regions south of the Yangtze River and southern China, the center said.
The observatory forecast downpours of up to 120 millimeters in some areas of Jiangxi, Fujian and Hainan provinces.
Under a strong cold snap, Yunnan and Guizhou will see temperatures drop 4 to 8 degrees in the next three days, it added.
The national meteorological center also warned of moderate to heavy snow in northwestern and northeastern parts of Yunnan and western areas of Guizhou today.