Fireflies by State 2025

Tennessee

The United States is home to some of the most diverse climates and wildlife in the world, due to its sheer size which spans multiple time zones, climates, and topographies. Not only are there many different locations to view fireflies within Tennessee, but it is one of the best places in the world to view them in their natural habitat and appreciate their colorful splendor. The best place to see the fireflies is in the Great Smoky Mountains, and they are extremely active between May and June, depending on the soil quality, temperature, and air conditions.

Of course, to see the fireflies in their natural luminous wonder, it is best to venture out at night to see the contrast of the landscape being illuminated by the light of the fireflies. Be careful to come prepared or with a guide, as it can be dangerous to venture out into the woods and the mountains, especially at night. Fortunately, the Great Smoky Mountains National Park has many shuttles available for just this reason, and it is best to call ahead to check on availability and explore different packages.

Pennsylvania

Although this state may not be the first one that comes to mind when thinking about outdoor activities, wildlife, and excursions, Pennsylvania has an impressive firefly population that can be seen at different times of the year. Found within the delicate branches of the Allegheny National Forest, there are effective spots to watch for fireflies, especially in large numbers. For the longest time, before noticing the tucked-away secret of the fireflies in Tennessee, it was considered the number one location to catch a glimpse of the large swarms of fireflies that come out at night.

The state of Pennsylvania celebrates the Firefly Festival, which naturally occurs every 4th Saturday in June. Although they can usually be seen in the off-season, this is the best time to attend, as you can also take part in the activities, celebrations, and other festivities that the festival has to offer. Live music, camping, and guides are waiting to show you the natural beauty of the firefly season.

Florida

Fireflies are just like any other insect, they love the hot and humid conditions, especially in swamps and marshes. Fireflies live and thrive in this environment, which is one of the top climates in many regions of Florida. Blue Spring State Park is the number one place in the state of Florida, and possibly even the United States, to view an agglomeration of many different fireflies. In contrast to the summer months in other states, Florida’s peak season is during mid to early spring, usually around March and April. This is because the climate is very hot year-round, and the summer season brings extremely hot conditions which decrease the air quality of the swampy environment.

Visitors need to receive a special pass to stay in the park after it closes, as the fireflies typically come out after dusk, and are best enjoyed when night has fully settled in.

South Carolina

Lightning Bugs, sometimes referred to as “fireflies”, can be found only in certain areas. Americans are fortunate that they have one of the best locations in the world, which is Congaree National Park, located in South Carolina. Lightning bugs are more common than one may think, as there are over 2000 known species across the globe. The issue lies in the ability to see them. Only a handful of the 2000 species are synchronous - meaning that the bugs themselves need to light up at the same time to produce enough of a marker to alert everyone of their presence.

Only the male bugs flash, and getting them to do so at the same time is a wonderful experience. Male lightning bugs do so to attract mates, signal their intention and locations or even do so as a warning sign to other critters and competitors. Congaree National Park is home to one of the rare synchronous species called Photuris Frontalis. For about two weeks of the year in the summer, the males put on an incredible and beautiful show of rhythmic flashes for everyone to see. Of course, during these two weeks, the competition for mating is fierce.