Where To See Synchronous Fireflies 2024 Mumbai. The festival is held from may third week to june third.  — synchronous fireflies (photinus carolinus) are one of at least 19 species of fireflies that live in great smoky mountains national park.

 — synchronous fireflies (photinus carolinus) are one of at least 19 species of fireflies that live in great smoky mountains national park. We’re going to tell you everything you need to know to get the best chances of seeing the spectacle, plus some.