On Friday, visibility in sections of Beijing was less than 200 metres (219 yards) due to strong pollution, which forced the shutdown of some routes.
On Thursday, Beijing issued its first fall and winter heavy pollution notice, ordering the suspension of some outdoor construction, manufacturing operations, and outdoor school activities.
The tops of the city’s tallest skyscrapers have vanished in the haze, drastically limiting visibility.
In the fall and winter, the heavily industrialised Beijing-Tianjin-Hebei region frequently experiences thick smog, especially on days when there is no breeze.
A cold front forecast to arrive from Siberia this weekend might help to disperse the smog.
China’s environment ministry stated last month that it wants to reduce PM2.5 concentrations in major cities by an average of 4% year on year this winter.
According to the US Embassy in Beijing, the PM2.5 level in urban areas hit 234 micrograms per cubic metre on Friday, indicating highly unhealthy air.
According to the government, China’s comprehensive winter campaign against pollution in 2021-22 would be launched in as many as 64 cities across the industrialised, smog-prone north.
The Winter Olympics will be held in Beijing and Zhangjiakou, China, from February 4 to 20.