Synchronous Fireflies at Congaree

Fireflies blink along the forest floor at dusk
Synchronous Fireflies light up the forest at dusk. (NPS Photo)
2020 Synchronous Fireflies Season
Updated on March 2, 2020
Original Post: November 15, 2019

The 2020 Congaree Fireflies Festival
Over the past several years, Congaree National Park has seen a dramatic increase in the number of visitors traveling to the park to witness the synchronous fireflies phenomenon. The park has sought to provide visitors with safe and enjoyable experiences, while also protecting the fireflies and their habitat. Each year, park staff have instituted new programs and have adjusted park operations in order to accommodate the increasing number of visitors. Below are important changes to the Fireflies Festival that will be implemented in 2020.

Changes being implemented for 2020:

To ensure visitor safety, protect firefly habitat and to provide the best viewing experience possible, the following changes are being implemented for the 2020 Congaree Fireflies Festival:

  • In response to visitor feedback about over-crowding on busy nights, there will be a nightly limit on the number of visitors admitted to the event. Specific details about the process for reserving tickets will be announced in early 2020.
  • The designated Fireflies Trail will be lengthened to increase spacing between visitors to allow for better viewing conditions and access to additional prime viewing locations.
  • The first section of the Boardwalk will be under construction at that time. Because of this, the sidewalk behind the Visitor Center and the Picnic Shelter will be reserved for visitors with mobility issues.
  • The park has planned the 2020 Congaree Fireflies Festival dates (May 11-24) based on scientific observations over the last few years. The fireflies are ultimately on Nature’s calendar, however, so we cannot guarantee that the festival dates will correspond to peak activity. Visitors will still have the opportunity to view fireflies in their natural habitat and park staff will be there to help visitors make the most of their experience.
  • There may be additional changes to this year’s event, so be sure to check back here again.

Timeline of how the Congaree Fireflies Festival has grown and changed over the past few years:
  • Pre-2014: The fireflies have been observed for many years. Some locals and visitors know about the synchronous phenomenon, but it is not an event. A long-term decline in firefly populations coupled with increasing light pollution, however, make such experiences increasingly rare for many.
  • 2014-2016: Park staff begin noticing a marked increase in the numbers of visitors coming to the park to see the fireflies. Law enforcement rangers begin staying late on evenings to monitor the situation. Reports of habitat disturbance and frequent visitor complaints about the noise and light pollution from other visitors are recorded. Visitors are observed parking on the Entrance Road, making it nearly impossible for emergency vehicles to have access to the park. Most visitors are from the local area.
  • 2017: Extended hours are implemented for the Harry Hampton Visitor Center, which stayed open till 9:00pm for eleven days. The Fireflies Festival was a one day event. Several hundred visitors attend the festival.
  • 2018: Visitor Center hours are extended to 10:00pm nightly and the Fireflies Festival becomes a ten day event. A designated Fireflies Trail is created to protect firefly habitat and to offer visitors unobstructed views of the fireflies. The Boardwalk is reserved for visitors with mobility issues. Park staff, volunteers and community partners conduct parking operations to assist visitors with parking along the Entrance Road. Several thousand visitors attend the festival. In addition to local residents, more and more visitors are starting to come from the surrounding region for the event.
  • 2019: Park staff manage the firefly festival through the Incident Command System for the first time, which is a standard approach for government agencies and partners to manage complex events (i.e. natural disasters, major events, etc.). Park staff create a roadside pedestrian walkway and institutes full traffic control operations to prevent vehicle-pedestrian encounters. Park successfully pilots a shuttle program with COMET during Memorial Day Weekend to bring visitors into the park from the State Fair Grounds in Columbia. Paramedics are on duty for the entire event. 12,000+ visitors attend the 18-day Fireflies Festival. Visitors are coming from all across the nation for the event and media requests are coming in from as far away as Europe.
General Fireflies Viewing Information:

Because of the large numbers of participants expected for this event, the following are prohibited on the Fireflies Trail:

  • Dogs (service dogs allowed)

  • Strollers or wagons

  • Flash photography

  • Headlamps

  • Using Smartphones as Flashlights

  • Chairs, hammocks or blankets

  • Smoking/Vaping

  • Alcoholic beverages

  • Applying insect repellant (please apply prior to arriving at the park)

Participants are asked to observe the following viewing etiquette:

  • Keep noise levels to a minimum so that everyone can enjoy this special natural occurrence.

  • Capturing fireflies is not allowed within Congaree National Park.

  • Stay on the designated trail (walking off trail can adversely impact firefly habitat).

  • Wear sturdy, close-toed shoes (roots and biting insects may be present)

  • Only use flashlights when absolutely necessary, pointing them straight down so as to not disturb other participants (Small penlights are recommended).

Other important information about the Congaree Fireflies Festival:

  • Be prepared for the weather. Thunderstorms often occur in the evenings during May.

  • The best time to view the fireflies is just after dark, usually between 9:00pm and 10:00pm.

  • Because of the high volume of visitors, backcountry campers will only be able to access the backcountry via Kingsnake Trail at the South Cedar Creek Canoe Landing. Vehicles of backcountry campers must be parked at the parking lot located at that site. All visitors wishing to camp in the backcountry must have a permit.

  • If you have a specific question not otherwise answered on this page, please e-mail us

  • If you are interested in volunteering at the 2020 Fireflies Festival please e-mail us.

With over 2,000 species found world-wide, there are only three species of synchronous flashing fireflies that can be found in North America. Every year, Congaree National Park hosts synchronous fireflies for approximately two weeks between mid-May and mid-June. During this time visitors can experience an awe-inspiring display of synchronous flashing while the fireflies search for a mate. For information on the scientific research of fireflies at Congaree National Park, be sure to visit the Old Growth Bottomland Forest Research and Education Center's fireflies page.


Last updated: March 2, 2020

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