A woman rides an electric bike in heavy fog that blanketed Binzhou of East China’s Shandong Province on Sunday. The province issued a red alert warning on Sunday morning, as 11 Shandong cities were affected. Photo: VCG

 
Thick fog that has shrouded most parts of north China over the past few days will be dispersed Wednesday as a cold wave is sweeping across the region.

The National Meteorological Center renewed a yellow alert for fog, warning that visibility in parts of Beijing, Hebei, Henan, Shandong, Jiangsu, Hubei, Liaoning, Sichuan, Xinjiang will be reduced to less than 200 meters or even 50 meters on Tuesday morning.

However, as a cold front is sweeping southward, foggy weather will come to an end on Wednesday, the center said.

The presence of fog was mainly due to unfavorable weather conditions including high humidity, temperature inversion and stable air, said Wang Zifa, a researcher with the Institute of Atmospheric Physics of the Chinese Academy of Sciences.

Heavy fog has enveloped the northern and central parts of China over the past four days, prompting 55 cities to issue alerts and reduce pollution.

China has a three-tier color-coded warning system for fog, with red being the most serious, followed by orange and yellow.