Mesmerizing clouds resembling cotton candy appeared over Sandu Sumu, Horqin Left Rear Banner in Tongliao City, north China's Inner Mongolia Autonomous Region on June 5.

This natural phenomenon is called mammatus clouds. When cooler air from the downdrafts meets warmer air from the updrafts, mammatus clouds form, often occurring in conjunction with thunderstorms.

Watch this video from Weather China, the China Meteorological Administration's online weather service, to find out more.

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