Beijing is once again sitting in smog. China’s weather authority has issued a yellow alert since Tuesday for Beijing, and neighbouring city of Tianjin and Hebei Province.

It’s the third highest on the four-level warning system. Official air quality index surpassed 300 at noon on Tuesday, that’s a level deemed "hazardous" to health. And readings remained between 250 and 300 in the afternoon.

With the air "heavily polluted", people are advised to put on facemasks and reduce outdoor activities, especially children and the elderly. To control dust levels, traffic authorities are spraying more water to clean the roads, while construction sites are requested to cover up rubble piles. But Beijing residents should be able to breathe easy again on Friday, when a cold front is forecasted to arrive and disperse the smog.