BEIJING -- Affected by "adverse atmospheric diffusion conditions," heavily polluted weather is like to haunt the Beijing-Tianjin-Hebei area and its surrounding regions in the next 10 days, an official forecast said Saturday.

Beijing, in particular, will see a drastic change in air quality, with moderate or serious pollution to come from Dec 19 to 22. The arrival of northernly winds will help improve the city's air quality starting from Dec 23.

Air pollution in the Beijing-Tianjin-Hebei region will gradually ease around Dec 24 thanks to a cold air effect, said the Ministry of Ecology and Environment in an air quality report for the rest of December.

In the Yangtze River Delta, air quality is expected to stay good or slightly polluted, while in Fenhe and Weihe river basin in Shanxi and Shaanxi provinces, the chances of lasting serious air pollution are slim.

In the next 10 days, air quality in northeastern China will be about average. The central and western part of Liaoning however might suffer from moderate or serious air pollution on Saturday, with PM 2.5 being the primary pollutant. The pollution process will gradually ease from Sunday to Monday thanks to good atmospheric diffusion.

Air pollution of various degrees is also likely to appear in southern, southwest and northwest China.