Another round of sandy, dusty weather was expected to reach Beijing at around 11 am on Thursday, the Beijing Meteorological Service said.
Strong winds and heavy dust were already sweeping across Zhangjiakou, Hebei province, according to the service.
The primary pollutant in Beijing's air is PM10 — particulate matter with a diameters of 10 microns or smaller on Thursday morning.
Affected by Mongolian winds, the capital will experience sand and dust on Thursday afternoon and then into the night. Its short-term PM10 concentrations may reach heavy levels, according to Beijing Environmental Protection Promotion Center. The public has been advised to take precautions during the sandstorm.
Baotou, in the Inner Mongolia autonomous region issued a yellow alert for dust early on Thursday at 2:10 am. The city's observatory forecast that visibility would remain less than 1,000 meters in Baotou's northern mountainous region for 12 hours.