Weather sparks firefly mania, but will it last?
Americans may disagree on whether to call them fireflies or lightning bugs, but the weather has made for a great year for the blinking bugs.
Fireflies are lighting up summer evenings in greater numbers this season thanks to damp soil, steady rainfall and ideal breeding conditions.
Have you noticed hundreds of fireflies lighting up your yard this summer? You're not alone. From the Midwest to the East Coast, many people are seeing more flashes in the night sky than usual — and the weather may be playing a big role.
Firefly expert Christian Krupke told AccuWeather's Ali Reid that drought is the worst enemy of the fireflies, also known as lightning bugs in some areas.
A firefly blinks at night (Getty Images)
"We got timely rains [this year], though we’ve been in drought for years. Fireflies like moisture and moist soils; they’re not a species that likes the dry conditions," Krupke explained.
Wet spring, mild winter was conducive to a bountiful year
A winter that was slightly warmer than the historical average and a wet spring helped firefly larvae thrive underground during a critical phase in the firefly life cycle.
The period from December to June was unusually wet in much of the East, AccuWeather meteorologists found. The wettest weather compared to the historical average was from Texas to Ohio.
"We saw a lot of fireflies that were mating and laying eggs, so we should have a large population of larvae going into overwintering. That’s good," Krupke added. Overwintering is the process by which organisms pass through, or wait out, the winter season.
Iowa State University insect diagnostician Zach Schumm told Axios the fireflies have experienced perfect conditions to reproduce since last year in Iowa. Echoing what Krupke said, the warmer winter and rainy spring have helped their larvae, Schumm said, and the effect could last into next summer.
A long-exposure photo of fireflies in State College, Pennsylvania on July 4, 2025.
Popular Science says that parts of Pennsylvania and Illinois are reporting big concentrations of the blinking bugs this summer. Cities like Washington, D.C., and New York City have also had more firefly activity, which is a bit surprising because habitat loss and light pollution have been listed as contributing to their demise for years.
Michael Raupp, an entomologist at the University of Maryland, also quotes the winter weather as the cause for the upswing in reports of the bugs, and points out that it's not just them, but their prey that benefitted from the weather conditions.
'Fireflies' or 'Lightning Bugs?' It depends on where you live
Although it's not clear why, most residents of the western U.S. call the bugs "fireflies," while people in the Midwest and Southeast say "lightning bugs." Business Insider theorized that it could be because there's more lightning in the Southeast and more wildfires in the West, but they didn't consider that a good part of the East uses either interchangeably.
Climate change, other factors have bug populations on the decline
In addition to declining habitats and light pollution, climate change is a long-term threat to firefly populations, Penn State says. Extreme temperatures and precipitation changes can make for poorer conditions for the larvae, resulting in fewer fireflies in summer.
"Whether that’s an indication that the populations are rebounding, I wouldn’t go that far," Krupke said.
"Just because the weather is warm one day and cold the next doesn’t indicate anything about long-term trends, and with fireflies and many insects, the trends long-term are in decline, so I would expect that to continue."
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