In the butterfly valley of Ma'andi Township, nestled within southwest China's Yunnan Province, an extraordinary spectacle unfolds as tens of millions of butterflies emerge from their chrysalises.

Beginning on May 18 and expected to peak around May 22, this yearly phenomenon is expected to continue until June 20. 

Local butterfly experts, monitoring 23 sites, estimate that approximately 100 million butterflies will grace the valley this season.

Warmer temperatures and increased rainfall have spurred this year's "butterfly boom," arriving slightly earlier than usual, said Yang Zhenwen, curator of the Jinping Butterfly Valley Museum. 

"There will be about 20 million butterflies flying in the Yingpanshan mountain area, which is the best place to observe them," said Yang.

Experts say this abundance of butterflies is a testament to Yunnan's excellent ecological environment. 

Situated on a low-latitude plateau, Yunnan boasts diverse climates and flourishing ecosystems, providing an optimal habitat for these delicate creatures. Abundant vegetation, teeming with flowers and plants, ensures an ample food supply, while Yunnan's geographical position fosters a rich diversity of butterfly species.