From the 13th to the 16th of March 2021, an extremely strong dust storm struck Mongolia and northern China successively, causing 590 herdsmen to disappear and 16 people to die in Mongolia. When the dust storm reached central Inner Mongolia in the early morning of 15 March, the gust speed reached up to 40 m s−1, which is equivalent to the intensity of a grade 12 typhoon. When it arrived in the Beijing–Tianjin–Hebei region on the morning of 15 March, visibility decreased sharply and the concentration of coarse particulate matter in the air over Beijing reached as high as 9000 μg m−3 locally. Research shows that extreme dust-storm weather such as this is caused by the rapid intensification and eastward movement of a Mongolian cyclone.