The synchronous fireflies (Photinus carolinus) are an amazing natural spectacle, lighting up the Great Smoky Mountains National Park each year. This rare phenomenon has become so popular that the National Parks Service uses a lottery reservation system to manage viewings.
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The 2025 Firefly Season
The dates for the 2025 synchronous firefly viewing opportunity in the Great Smoky Mountains National Park have been announced. The event will take place at Elkmont from May 29 to June 5, 2025.
Lottery Information
Due to the event’s popularity, the National Park Service uses a lottery system to give people an equal chance of getting a ticket:
- Friday, May 2 at 10 am EDT: Lottery opens
- Monday, May 5 at 11:59 pm EDT: Lottery closes
- Monday, May 13: All lottery applicants will be notified if their application was successful or unsuccessful
- May 29-June 5: Annual firefly viewing opportunity
In total, 960 vehicle reservations will be available during the eight-day event (120 per night). This is 160 fewer slots than 2024, due to parking capacity and the need to safely accommodate viewers while minimizing resource impacts.
How to Enter the Lottery
To enter the lottery, visit www.recreation.gov.
- There is a limit of one lottery entry per household
- Applicants can choose two potential dates
- Each reservation allows one vehicle with up to seven occupants
- All applicants will be charged a $1.00 application fee
- Successful applicants will be charged a $29.00 reservation fee (an increase from 2024)
The reservation fee covers the cost of the reservation, on-site portable restrooms, supplies, and personnel costs for managing the viewing opportunity.
Access Restrictions
- Access to Elkmont will be limited to vehicles with reservations and campers staying at the Elkmont Campground after 12 pm during the viewing period
- Overnight parking at Little River Trailhead, Jakes Creek Trailhead, or the Appalachian Clubhouse will not be allowed
About The Fireflies
Fireflies, or lightning bugs, spend most of their life in larval form, feasting on snails and worms. Adult fireflies live for 3-4 weeks, often without feeding.
Their flashing patterns, varying in color from greenish-yellow to blue or white, are unique to each species and play a role in mating rituals.
The Phenomenon of Synchrony
The synchronous fireflies (Photinus carolinus) in the park have synchronized flashing patterns—a series of 5-8 flashes followed by an 8-second pause.
Synchrony ensures that female fireflies can recognize males of their species, which is important in a habitat with predatory firefly species!
When to Witness the Display
The mating season, lasting 2-3 weeks, varies annually based on weather conditions.
Peak activity typically ranges from late May to mid-June, which can vary based on rain and temperature. The best viewing occurs on misty evenings or when the temperature is above 50º Fahrenheit.
Viewing Etiquette
- Use red cellophane-covered flashlights or red light filters
- Keep flashlights pointed at the ground
- Turn off flashlights once in your viewing spot
- Avoid capturing fireflies, stay on trails, and pack out trash
History of the Lottery System
Since 2006, the National Park Service has used the lottery system for synchronous firefly viewings to reduce traffic congestion in the Great Smoky Mountains National Park while minimizing disturbance of the glowing beetles during their peak mating season.
Prepare for a special Experience
If you’re lucky enough to attend, the synchronous firefly event in the Great Smoky Mountains offers an amazing display of nature’s wonder!
2026 Update
The National Park Service set the 2026 Elkmont synchronous firefly viewing window for May 20-27. The vehicle reservation lottery opened April 24 at 10 a.m. EDT and closed April 27 at 11:59 p.m. EDT, with applicants notified by May 6.
During the official viewing window, nighttime access to Elkmont is limited to vehicles with a reservation and registered Elkmont Campground guests on foot. The lottery exists because demand is high and the park is trying to protect the fireflies, reduce traffic, and keep the viewing area manageable.
For the current annual schedule, use the NPS firefly page: Synchronous Fireflies - Great Smoky Mountains National Park.