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Live · updated todayTypical peak look

Great Smoky Mountains, Tennesseesynchronous fireflies

Out of season: the next synchronous fireflies season is in 2027.

Right now in Great Smoky Mountains · September

  • Cades Cove car-free Wednesdays · May–Sep

235days to the next synchronous fireflies seasonusually May 21–Jun 10

Typical timing
May 21–Jun 10
Typical timing, not a forecast yet

Next 7 days

  • Rain likely · up to 63% chanceSunday, Sunday Night

National Weather Service forecast, issued Mon 7:06 AM (Eastern). Frost: a low of 36°F or less; wind: 20 mph or more; rain: 60% chance or more.

The park's viewing nights, past years

8 seasons of park announcements, 2015–2026

Great Smoky Mountains opens for a few nights each year around the peak it predicts. Here are those nights, season by season, as the park announced them.

Jun 1
2015
Great Smoky Mountains, Tennessee, 2015: Jun 2–9
2016
Great Smoky Mountains, Tennessee, 2016: not on the park's website
2017
Great Smoky Mountains, Tennessee, 2017: May 30–Jun 6
2018
Great Smoky Mountains, Tennessee, 2018: not on the park's website
2019
Great Smoky Mountains, Tennessee, 2019: not on the park's website
2020
Great Smoky Mountains, Tennessee, 2020: canceled
2021
Great Smoky Mountains, Tennessee, 2021: Jun 1–8
2022
Great Smoky Mountains, Tennessee, 2022: Jun 3–10
2023
Great Smoky Mountains, Tennessee, 2023: Jun 4–11
2024
Great Smoky Mountains, Tennessee, 2024: Jun 3–10
2025
Great Smoky Mountains, Tennessee, 2025: May 29–Jun 5
2026
Great Smoky Mountains, Tennessee, 2026: May 20–27

Bars are the nights each park opened for viewing, announced weeks ahead as its predicted peak (not an observed peak). Empty rows: no announcement on the park's website.

Sources (9)

Great Smoky Mountains through the year

  • Snow most likelyJan–Feb
  • Spring wildflowersApr–May
  • Cades Cove car-free WednesdaysNowMay–Sep
  • Synchronous firefliesMay–Jun
  • Elkmont closed after noon on firefly nights (reservations and campers only)May–Jun
  • Fall colorOct–Nov

Where to watch

  • ElkmontThe viewing area: open at night only to reservation holders and campers during the eight nights
  • Elkmont CampgroundRegistered campers can watch without a vehicle reservation

How we know

National Weather Service forecast and alerts (opens in a new tab) (Sep 28) · National Park Service, Great Smoky Mountains firefly viewing dates, 2026 news release (opens in a new tab) (Sep 27) · National Park Service, Great Smoky Mountains synchronous fireflies (opens in a new tab) (Sep 27) · National Park Service, Great Smoky Mountains wildflowers (opens in a new tab) (Sep 26) · National Park Service, Cades Cove (opens in a new tab) (Sep 26) · National Park Service, Great Smoky Mountains fall color (opens in a new tab) (Sep 26) · National Park Service, Great Smoky Mountains weather (opens in a new tab) (Sep 26)

All our sources and how we use them →

Questions people ask

When are the synchronous fireflies at Great Smoky Mountains in 2027?

There's no forecast yet. In a typical year it peaks May 21–Jun 10. The park announces its viewing nights each spring, and we add them here when it does.

Are the fireflies flashing at Great Smoky Mountains right now?

Not now: the synchronous fireflies season is over for this year. The next one starts in about 235 days (usually May 21–Jun 10).

How do I get tickets, and what do they cost?

Enter the lottery on Recreation.gov in late April and pick two nights, a first choice and a backup. Everyone pays $1 to apply; if you're picked, $29 more buys a vehicle reservation for one night. In 2026 that was 120 vehicles a night, up to seven people in each.Sources: National Park Service, Great Smoky Mountains synchronous fireflies ↗ (opens in a new tab), National Park Service, Great Smoky Mountains firefly viewing dates, 2026 news release ↗ (opens in a new tab)

How are the viewing nights chosen?

The park predicts the peak from soil temperatures and opens Elkmont for the eight nights it expects to be best. The dates come out in late April (April 21 in 2026).Sources: National Park Service, Great Smoky Mountains synchronous fireflies ↗ (opens in a new tab), National Park Service, Great Smoky Mountains firefly viewing dates, 2026 news release ↗ (opens in a new tab)

How long does the season last?

About two to three weeks. A few fireflies flash at first, more join until the display peaks, then it slowly fades. Since 1993 the peak has fallen between the third week of May and the third week of June.Source: National Park Service, Great Smoky Mountains synchronous fireflies ↗ (opens in a new tab)

What if it rains or turns cold?

Heavy rain usually stops the flashing, while mist usually doesn't. Nights below 50°F also mean fewer fireflies in the air.Source: National Park Service, Great Smoky Mountains synchronous fireflies ↗ (opens in a new tab)

What should I bring?

A flashlight covered in red cellophane or with a red filter, pointed at the ground and switched off once you've found your spot. Stay on the trails: the females wait on the forest floor, and stepping off-trail can crush them.Source: National Park Service, Great Smoky Mountains synchronous fireflies ↗ (opens in a new tab)

Where are the best spots in Great Smoky Mountains?

Elkmont: the viewing area: open at night only to reservation holders and campers during the eight nights; Elkmont Campground: registered campers can watch without a vehicle reservation.

Are there closures or permits to know about in Great Smoky Mountains?

Elkmont closed after noon on firefly nights (reservations and campers only) (May–Jun); Elkmont: the viewing area: open at night only to reservation holders and campers during the eight nights; Elkmont Campground: registered campers can watch without a vehicle reservation.

What is Great Smoky Mountains like through the year?

Spring wildflowers (Apr–May), Synchronous fireflies (May–Jun), Cades Cove car-free Wednesdays (May–Sep), Fall color (Oct–Nov), Snow most likely (Jan–Feb) and Elkmont closed after noon on firefly nights (reservations and campers only) (May–Jun).