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When Will The Fireflies Light Up Your Back Yard?

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 damper the soil, 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)!

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 Fireflies 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.

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 backyard? Leave us a comment and “enlighten” us!

Check out these interesting facts about fireflies!

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  • Gail says:

    Just saw first one June 1 2020 south of Pittsburgh.pa. Thought I was seeing things.

  • Claudia says:

    Last year 2019 i had thousands. This year i see maybe five per night! What is up?

  • Me me says:

    i just wanted to know what time they might come out but they didn’t say that’s the only reason why i clicked on this

    • Susan Higgins says:

      Of course we wouldn’t have exact dates, Me me, we are providing you with information about the conditions needed for them to arrive in your neck of the woods. Every location is different. So if you had lots of dry weather, it might take a bit longer.

  • Js says:

    May 2, 2020 I saw a few flashes of lightning bugs this evening in south eastern Pa (chesco)

  • Morgan says:

    May 1st, first sighting of the year in Central Kentucky.

    • Susan Higgins says:

      Excellent, Morgan! We wonder if it won’t be until the middle of August before we see them here in Maine!

  • Bob King says:

    Started seeing them a couple of weeks ago (beginning of April) in New Braunfels, Texas. Then a snap of cool weather put them back into hiding. Today it warmed up substantially and at dusk the front yard was full of them for about 20 minutes.

  • Rita M Shaw says:

    I’m in RI, and I’ve seen firefly’s in over 20 years? I have moved into a apartment with a deck, that has slot of trees and a small pond.. So that could be it, but I’ve been to numerous camping grounds for years in RI Mass, Ct, without luck until 2018
    There was alot of them. It was raining.
    But what shocked me was I remember them glowing a soft yellow? Now they glow Neon White?
    I wonder why?
    But I am so happy to have them back.. my children and grandchildren didn’t believe me that they existed… So sad to lose a magical insect. It would be like losing dragonfly’s..

  • Jason says:

    1st night to see fireflies this season — April 16, 2020 — in the NW corner of Arkansas.

  • Liz says:

    We are seeing fireflies here in middle tn right now. They seem to be larger and brighter than any we usually see. Maybe a different species of fireflies. We do live next to a deep wooded area.

  • Mary Shannon says:

    I havent seen any lightenig bugs in a long time. But i really want to ,so im gonna really pay attention this year.im 65 now and remember catching them when i wasa little girl. Would love to see some again!

  • Jessica W says:

    4/5/2020. Have lived in the south my entire life, and while I’ve ways enjoyed fireflies in June, I was perplexed by the firework show this evening. It’s been warm and rainy…but early April?! And the abundance of lights is insane. I have only seen the Smokey Mts show once and this was on par. I actually woke my husband up because I honestly wondered if I was seeing things lol. What a rare and bizarre treat.

  • Baylee says:

    I have fireflies and I dance with them their buttiful

  • Jeremy Brookshire says:

    I live in Weaverville North Carolina. It is January 16, 2020. We have heard a great deal of rain lately and much higher temperatures than normal. This morning I awoke at 6:00 to the sound of what I thought was crows outside. I kept thinking it’s very early and dark for the crows to be so active. We have a small balcony off of our bedroom and I went outside and listened and it sounded very much like frogs. So this in and of itself was confusing to me for this time of year. I was born and raised in western North Carolina and pretty used to the patterns of animals and what happens in the winter time around here. But then folks I was completely floored when I turn my attention to the little sparkly lights all over the hillside and the white pine tree tops beside our house. I rubbed my eyes and looked again and I kid you not there were lightning bugs this morning! I didn’t even believe it so I asked my lady to come outside and look with me and she saw it too! So as I sit here eating my cereal getting ready for work I am completely perplexed by the situation and I have googled why this might be happening. Of course the warm temperatures and rains could help explain it but it’s January folks!?! Has anyone else ever heard of this happening before? I’m very interested in hearing if anyone else has ever witnessed this in our area this time of the year ever before.

    • Susan Higgins says:

      Hi Jeremy, lots of insects come out of their dormant state when the weather turns suddenly warmer — you were treated to a rare sight! Lightning Bugs are a type of beetle and they came out when they thought it was warm!

  • KayLynn watts poland says:

    I hv always loved fireflies. Rememind of summers past when folk sat outside and kids played and went in with containers that lit up in there rooms. Didn’t see them in New Mexico? Can’t remember in Florida. But here in tn they are still out in this hot sept. Weird

  • Marylee Kott says:

    In San Leon, Texas, west of Galveston Island. Saw a rare fireflly last year and decided to try to make a better habitat with grasses. Last weekend had many mating couples out in the yard. This weekend, nothing. I hope they were successful in starting a new generation.

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