July 6-7, 2019

Theme: “Fireflies need dark nights

Dear Fireflyers,

We’re so excited to announce this second annual World Firefly Day!

Our theme this year – fireflies need dark nights – highlights a growing threat to these charismatic insects. All around the world, cities’ bright lights are erasing natural darkness. Light pollution interferes with biological rhythms and blinds us to the beauty of night. It also puts fireflies at risk. Brightly lit areas obscure their magical glow, making it difficult for fireflies to detect their bioluminescent mating signals. So we hope you’ll join us in celebrating World Firefly Day 2019 by dimming your lights in recognition of the sheer delight these night-time wonders bring to us all.

Flash on!

Sara Lewis
Chair, FIN Steering Committee


The California Institute of Environmental Design & Management (CIEDM) held an evening meetup on the subjects of both World Firefly Day 2019 (July 6-7) and National Moth Week 2019 (July 20-28) with a focus on the needs for light pollution control. The event, registered with National Moth Week and attended by CIEDM staff & friends, took place at Arcadia EcoHome encompassing a yard which is a certified Wildlife Habitat, Pollinator Garden and Bee Friendly Farm, in Arcadia, California, on July 12th. After a brief introduction and discussion, Dr. Edward Huang, CIEDM Principal, guided a walking tour of the yard featuring landscape elements of lighting and habitats for various night species are conducted under dark sky.

The second Portuguese World Firefly Day was held in Ayamonte (Huelva), a village near the border with Portugal, in a beautiful environment of marshes on the Atlantic Ocean coast. After the exposition in the Visitors Center of the Natural Protected Area of Isla Cristina Marshes, we went out for a night walk. Near sixty people (mostly kids that had been brought by their parents) went through the pathway, listening to the squeaky melody of the crickets and playing to discover stars above and under us. It was not the best day for the activity, because the peak of glowworms emergence is over. But a tiny companion had come with me because she wanted to be sure that all our friends would have a magical night. So when we had a halt and all the laterns were switched off, a delicate spark perched on my hand flooded with her light the darkness, filling with emotion the faces that were getting closer to us in ordered queue. A minute green glint, almost nothing compared with the powerful lanterns. No one of the kids and parents had ever seen a glow-worm: everybody was excited looking that smallness. And I guess all of us convinced ourselves that we really need dark nights: for us, to look the wonders of the nature, and for our tiny friend to be able to fall in love with some handsome flying Romeo...

For information about how to celebrate, please check out our announcement.

To look at photographs and write-ups from last year’s events, click here.