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When Will The Fireflies Light Up Your Back Yard?

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When Will The Fireflies Light Up Your Back Yard?

Catching fireflies (or “lightning bugs”) is a pastime we all look forward to every summer. But how soon should you get your Mason jars (and the palm of your hands) ready? Weather could give you a clue.

Yes, fireflies, which are actually a type of beetle, share a relationship with weather that goes deeper than the summer solstice. Their larvae live underground during winter, mature during spring, and then emerge in early summer anywhere from the third week in May to the third week in June. What dates you’ll begin to see fireflies in your back yard is somewhat of a mystery, and changes from year to year. But scientists do know that air temperature and rainfall have something to do with it.

Muggy Bugs
Unlike people, fireflies love warm, humid weather. It helps them to survive. So in years when summer-like weather arrives before June does, fireflies tend to appear in lawns, gardens, and trees earlier than usual — sometimes as early as late spring. All the warmth from early summers and mild winters fools lightning bugs into thinking it’s later in the season than it really is, and so they emerge sooner. Mild winters also mean a larger lightning bug population in your back yard, since the young will have had an easier time surviving the cold.

Wet springs also lead to earlier firefly flash displays — likely because firefly larvae feed on snails, slugs, and pill bugs which are brought out by rains. The more damp the soil is, the more plentiful these creepy-crawlers will be, and the more food young fireflies will have to carry them into adulthood. And it’s the adult fireflies that flicker (mostly as a way to attract mates)!

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As much as damp weather provides an ideal environment for fireflies, dry conditions provide the worst. Droughts and heatwaves stress firefly eggs and larvae, causing them to die off before they’ve had a chance to emerge. The dates when lightning bugs appear will also be delayed due to the heat stress.

Expect the Brightest Flashes on the Warmest Nights
Weather not only plays a role in how soon you’ll see lightning bug flashes, but how many flashes too. On warm and humid evenings, lightning bugs can light up a field as if it were a Christmas tree! But on cooler nights when air temperatures take a dip into the 50s, don’t be surprised if you wait a minute or longer to see a single flash. Why is this? Fireflies, like most insects, are cold-blooded (meaning they depend on heat from their surrounding environment to help them function), so their activity peaks when temperatures rise, and slows when temperatures drop.

With NOAA ranking the winter of 2017 as the sixth warmest on record, lightning bugs could emerge as soon as mid-May this year.

Or maybe you are planning to trek to the Great Smoky Mountains to view this year’s synchronous firefly display (it’s the largest population of synchronous fireflies in the Western Hemisphere, and begins May 30th ) Take a look at the video of this incredible event:

Have you seen fireflies yet in your back yard? Leave us a comment and “enlighten” us!

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1 Shannon { 11.27.17 at 9:51 am }

Seen an amazing firefly flash show on Nov 26 in Cold Ottawa winter in Canada! My backyeard trees were lit like a xmas tree from thousands of fireflies!! It look absolutely amazing and magical.
I didn’t think they can still be around in this time of the year. and I highly think they are attracted by neighbour’s mosquito trap light or buzz.

2 angel { 11.14.17 at 11:39 am }


3 Kimi Rowell { 10.30.17 at 6:46 pm }

I’m curious as to why I’m still seeing random fireflies here in San Antonio, Tx and its October 30, 2017. If anyone knows I’d love to find out!

4 sherry Gunn { 08.30.17 at 9:19 pm }

We have been seeing fireflies since May and all the way through to today, August 30, 2017. This has been the longest season for fireflies I’ve ever seen. Love the lightning bugs. Parker County, Texas

5 Virgie { 08.27.17 at 12:17 pm }

Denver, CO 9am bug crawling across the floor. I let it crawl on a paper to take it outside. It was a black beetle and it lit up red underneath. Not sure what it was. I’ve heard that there is no lighting bugs in Colorado. This is not the first time I have seen one of these bugs.

6 Susan Higgins { 08.10.17 at 8:51 am }

Bill Bean, interestingly, the spring rains would have kept them on schedule for summer; they may have had a second wave of hatching. It’s been dry here in Maine and we haven’t seen many at all.

7 Bill Bean { 08.10.17 at 1:09 am }

Saw Fireflies tonight (Wed., Aug. 9, 2017). Isn’t this rather late? Yes, this is Ontario, but in this area, June is the norm. We had some major rains in the late spring and early summer. Might the rain have delayed their cycle?

8 Jennifer Maggio { 07.04.17 at 11:53 am }

The lightening bug magic show here in our Southern New Jersey backyard is stunning this year! Last evening, July 3rd, from dusk until past dark, the whole woodsy area…and yard… and neighborhood …was sparkling nonstop with bright twinkling lights! Like 4th of July sparklers set free without sticks! We were enchanted beyond words.

9 Jack Gleaton { 06.29.17 at 11:04 pm }


For the first time this year this 73 year old white man just saw one(1) Firefly(Lightning Bug is the name used by the local people here in Southwest GEORGIA, USA about 70 miles North of the GEORGIA – FLORIDA state line) in his front yard under one of the three(3) River Birch trees about 8:45 PM. Later, about 8:55 PM in the backyard I saw two(two) more Lightning Bugs under an Old Wolf Pine tree.
It had been raining with a lot of lightning and thunder for about the past six(6) to seven(7) hours and prior to the rain it was very hot and humid. At the time of the sighting the temperature was about 72 – 73 degrees and 6(six) to 7(seven) miles per hour wind with heavy overcast sky.
I think my first time of remembering seeing a Lightning Bug was about one month after my fourth birthday on the 2nd of May.

10 Heather { 06.28.17 at 10:47 pm }

Beverly, MA…the last time I saw fireflies here was about 9 years ago. I always look for them but they seem to be disappearing from this area. Growing up in CT I would see tons every single year, but we lived in a damp region. Where I am now is surprisingly dry considering it’s a coastal town.

11 Diane Alden { 06.25.17 at 9:44 pm }

So far have only seen one firefly this year, today June 25, 2017. Tonight. Hoping for more. Hoping………………..

12 Dara Wegman-Geedey { 06.03.17 at 11:21 pm }

Saw our first 2 fireflies tonight 6/2/17 around 8:45 pm — one in our backyard, one in the front yard. Rock Island, IL

13 Darcy { 05.28.17 at 10:43 pm }

First firefly tonight outside of Rochester NY!

14 gandalf80 { 05.28.17 at 1:31 pm }

PLEASE do not encourage “catching” fireflies (or lightning bugs, as they’re called in east Tennessee)because they are endangered primarily by light pollution, but also habitat encroachment and insecticides. We can look with our eyes, not our hands.

15 Michelle { 05.26.17 at 12:34 am }

First night of fireflies here in Northern Alabama tonight, May 25th.

16 Tammy { 05.24.17 at 8:24 pm }

Yes lighting bugs may 15th beaverdam ky.

17 Valerie { 05.24.17 at 6:50 pm }

Frainy is Rainy!

18 Valerie { 05.24.17 at 6:47 pm }

It’s been an unusually wet, frainy, to the point of flooding, to make national news. Yet, confirmed the lightning bugs are out in Republic, Missouri!
Yes, I caught them as a kid, only to find them at the bottom of the jar the next morning. So when my kids were young, they caught them, brought them in, and let them go in their rooms…to watch them fly! Yet, still sadly, the next day to have found, they still die. (They learn, in just one summer.)

19 Carroll { 05.24.17 at 5:03 pm }

I live in Western North Carolina, haven’t seen any lightning bugs so far this year. I enjoy seeing them, makes me feel like a kid again!

20 Peggy { 05.24.17 at 3:44 pm }

We do not have them here in western Washington state, do not know if they do in eastern Washington state but don’t think so.

I saw them only one time in my life when I was visiting relatives in Trenton, Illinois. Thought they were pretty neat to watch. Didn’t want to catch them but loved watching them.

21 Debbie Johnson { 05.24.17 at 3:18 pm }

Saw a few a couple of nights ago in Benton Arkansas. But we have had an unusual wet cool spring, so far anyway, but you know what they say about Arkansas weather, “stick around, it’ll change!”

22 Phyl { 05.24.17 at 1:37 pm }

We need to show respect for these fireflies. NOT capture them in a jar! Not harm them! Parents must teach children respect for these creatures.

23 roy o { 05.24.17 at 12:34 pm }

Had 1 in my LR on the eve of 5/18/17 in Wind Gap Pa w/ hi/lo temps that day of 90/66

24 Sandy Johnson { 05.24.17 at 7:42 am }

I saw fireflies in my backyard on May 20, 2017. In fact, one person present was surprised to see them but now we know why! Thanks.

25 Keith giffin { 05.24.17 at 7:23 am }

Yep had fire files last night 5/23/17 in south central ohio

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