The air quality in Shanghai is currently severely polluted by PM10 particles blown from northern China, forecasters said.
This is the first round of serious air pollution since the city entered autumn.
At 11am, half of the city’s key monitoring stations showed readings of heavy pollution.
The air quality index soared to 358 at noon on Tuesday with the one-hour concentration of main pollutant, PM10 particles, hitting 466 micrograms per cubic meter.
The 24-hour PM10 concentration was 140 micrograms per cubic meter at 1pm, nearly triple the 50 micrograms per cubic meter which is considered safe according to guidelines of the World Health Organization.
People with heart or lung disease, children and the elderly are suggested to stay indoors, while everyone else is encouraged to avoid outdoor physical activities, the Shanghai Environmental Monitoring Center said.
Meteorologist from the local weather bureau told Shanghai Daily that since the city’s air condition is stable, pollutants carried to the city from the north have collected here.
But starting on Tuesday afternoon, northerly winds will turn easterly and carry the particles offshore, bringing clearer air.
The monitoring center also said the air quality is likely to be reduced to lightly to moderately polluted on Tuesday afternoon and evening.
As the dust departs, the air quality is expected to become good again on Wednesday.
The rest of the week will be mainly cloudy with the mercury ranging from 14 to 23 degrees Celsius. The lowest temperatures will be 14 to 16 degrees in downtown areas. The outskirts will be colder, with the low likely to drop below 10 degrees.