China has issued the first smog warning of the winter for the Beijing - Tianjin - Hebei region for 24 to 26 November . The yellow alert , issued by the Beijing Municipal Bureau of Ecology and Environment , means that heavy industry and construction sites will have to stop operating for the period . Additionally , 28 cities in Hebei , Shanxi , Sichuan and Henan province have issued orange - level smog warnings for the same period . Heavy industry is a problem for China 's northern region from mid - November to mid - December because of additional coal burning for power and heating by homes and utilities .
China has issued the first smog warning of the winter for the Beijing-Tianjin-Hebei region for 24 to 26 November. The yellow alert, issued by the Beijing Municipal Bureau of Ecology and Environment, means that heavy industry and construction sites will have to stop operating for the period. Additionally, 28 cities in Hebei, Shanxi, Shandong and Henan province have issued orange-level smog warnings for the same period. Heavy smog is a problem for China's northern region from mid-November to mid-March because of additional coal burning for power and heating by homes and utilities.