Tens of millions of butterflies have emerged from their chrysalises in the butterfly valley in Honghe Hani and Yi Autonomous Prefecture, southwest China's Yunnan Province, presenting an astonishing sight.

Due to warmer temperatures, the "butterfly explosion" this year occurred slightly earlier than usual, and the size of butterflies is larger than in previous years, according to Yang Zhenwen, curator of the butterfly valley museum in Jinping Miao, Yao, and Dai Autonomous County.

"We expect that there will be about 80 million to 100 million butterflies in the valley this year," said Yang.

In the butterfly valley, more than 320 butterfly species have been identified in specimens or photographs, including the rarest, most primitive, largest, and smallest butterflies in China.

The butterfly explosion is estimated to last until around June 10.