China has a four-tier smog warning system introduced in 2013. The highest red level warning is issued in case heavy smog conditions last for over three days, while orange is issued during three-day pollution spells, Sputnik reported.
"This morning, in portions of southeast Beijing, northern Tianjin, central and southern Hebei, Sichuan Basin, western and southeastern Chongqing, and northeastern Guizhou, heavy fog with local visibility down to less than 200 meters is predicted. What’s more, the visibility in some parts of these areas can even fall to less than 50 meters," the center said in a statement.
The previous orange warning was issued just days ago for December 2-4. PM2.5 pollution, which consists of suspended particles 2.5 micrometers or less in diameter, is at 252 micrograms per cubic meter compared to the recommended safe level of below 25 micrograms.
The situation is expected to improve on Monday.