When Will The Fireflies Light Up Your Back Yard?
Wondering when you'll see fireflies (or "lightning bugs") glow on these warm summer nights? Watch for this backyard clue!
Watching fireflies (or “lightning bugs”) is a pastime we all look forward to on summer nights. But when can you expect to see their subtle glow light up your backyard? 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.
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)!
While damp weather creates a wonderland for fireflies to thrive, they struggle in dry conditions. In the face of droughts and heatwaves, firefly eggs and larvae become stressed and often perish before they emerge. As a result, the enchanting effects of lightning bugs lighting up the night are delayed, their magical appearances postponed by 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!
Tiffany Means is a freelance writer and a degreed meteorologist. She specializes in weather forecasting and enjoys making the subject of weather (and the science behind it) more relatable. She currently resides in the Blue Ridge Mountains of North Carolina.
Fireflys came out in Liberty hill texas on May 6th 2023. Super early for us. However, it has been humid, wet and 92 degrees.
We have lightning bugs out right now. They came out March 31 , never seen them this early . In east Tennessee, close to the GSMNP .
Late August in central Indians see a few solitary fireflies close to the ground. Don’t believe I have ever seen them this late.
Last night in my ravine was truly glorious! Northern Ohio.
Thousands of Fireflies lighting up from the ground to treetops.
Was able to share this once in a lifetime moment with my youngest daughter.
How wonderful Jeffrey! They are amazing to see especially when shared.
Beautiful displays happening in the Ozarks, western Greene County.
Staying away from using any lawn applications for a number of years is paying off. The pasture and lawn seem to have three different varieties of lightning bugs based on flash and flight patterns, and light colors.
Visiting eastern Pa. parked in a field for the night and the fireflies are all aglow! It is so unexpected and magical!
Nature is amazing, isn’t it? Thanks for the idea.
I live in southwest PA. A few came out last week but the weather dropped and they disappeared. As of yesterday, they’ve been out and lighting up the trees!
I live outside of Houston, TX. I saw them about 3 weeks ago(mid May). But we have extremely humid weather. There are not many; but I get excited when I do see them. I try to sit outside every afternoon til dark and watch for them; that is if the mosquitos don’t carry me off.
I started seeing them already in May. I don’t think I’ve ever seen them out this early in Massachusetts before.
Saw my first fireflies last night here near Charleston SC ! Amazing!
Just saw the first lightning bugs tonight, on a still evening before a thunderstorm. Northeastern Connecticut. Seeing them is like a time capsule – they transport you back to childhood.
Just saw my first fireflies of the season. Got to get out my decoy light and go play with them
When I lived on Long Island we had an irrigation system installed in the early 90s. Something I noticed afterwards was an explosion of fireflies at night during summer, literally thousands. It was also a heavily wooded area. I moved to S. Carolina (midlands) last fall and and still haven’t seen any yet this year. Well I saw one during the day on my screen but not lighting at night. We had a dry spring so hoping now that the rain and humidity has started we will start seeing them. It’s not summertime without them lol.
SC sprayed insect poison heavily a couple years ago “to lower mosquito population’ it has affected all manner of insect life. Our firefly population has drastically decreased . We r in Union county NC just over the sc border.
I am in northeast Massachusetts. Couldn’t sleep! I went out on our back porch and almost called an eye doctor thinking I was seeing abnormal light flashes! You know the rest. I am in awe of this fabulous display! It is a very warm and muggy night. Owls are hooting; bill frogs croaking; our bird house is hardwired to a camera and all six week old hatchlings are sleeping.
All is well. ?
I just move to North Carolina. Charlotte. And have a creek and lots of foliage in my backyard. And last night I saw my very first firefly. It was the most magical thing ever. I’m so happy they live in my yard and am on the lookout tonight for more. It’s like tiny fairies dancing. I love this unexpected gift.
We use to have lots of lightning bugs in SE Texas, when I was a kid. They started spraying for mosquitoes and eventually it killed off the fire flies. I wish they would come back. I love ? those bugs!
I live in NH I have seen many different colored fire flies, none here yet
Saw Fire Fly’s in my back yard tonight for the first time. Sallisaw OK. Just moved here this year so it was so cool to see!
I’m in Missouri and last night I saw the most beautiful display of lightning bugs, but the strange thing was that it was in the low 50’s. We are just now experiencing spring. Why would I be seeing them in this weird pattern? And in April, when have been having such colder weather.
Firefly’s have been out for a week already in Davidsonville. I have never seen them before in mid April.
Can fireflies be seen in August?
Depending on where you live you should be able to see some fireflies in August.
watching some tonight in central NC, never seen any this early in the year
Seen some last night in Northeast Alabama. It’s been a super wet year so far and the Temps are finally getting warmer here.
We’ve got fireflies tonight, April 6th in north ga.
My wife and I live in Macon, GA and we observed fireflies in our backyard this evening (March 19, 2022). We’ve had a mild winter and the past few days have been relatively warm with significant precipitation. Even though I’m a newly retired biology professor with a Ph.D. in Entomology, I was surprised by such an early emergence.
I’m in South Fulton! Just stepped outside tonight and saw them! it seems awfully early, but saw tons of them flashing up in the top of the pines, figured they just came out in the last day or so! So happy that someone else sees them, we’re not crazy!! March 31, 2022
East Tennessee here and noticed quite a few this evening after a super heavy down pour and temps in the mid 70s through out the day. I had never noticed them this early!
tonight i saw glowworms in my backyard here in N.H. i’ve never before seen them, and i’ve lived here more than 50 years. not sure if they’re related to fireflies. must research.
Dale, we have a story on glowworms that might help. Take a look here.
I live in Cleveland, Mississippi, and Over the past year have thought I saw a single firefly a couple of times, but wasn’t completely sure – because it was just one single flash out of the corner of my eye. Amazingly, the other night, we saw about 10 fireflies – July 22, 2021. I haven’t seen any since.
Does any one know why this would be? I am not sure what their range is. Is it possible a new population is trying to establish in our area?
We are in an area with a large number of acres designated to agriculture: Soybeans, Corn, Rice, and maybe Cotton. According to people that have lived and grown up here, there used to be fireflies, but significant amounts of pesticides likely wiped out the majority of firefly populations. I have heard of firefly sightings about 6 miles away, so have been hoping they would find their way to us.
How close is your nearest farming community? We had them here as well in illinois, but this year there was a smaller amount and they have already died off. Normally this wouldn’t happen till later…some time in mid Aug maybe. The culprit is most likely a combination of insecticide and herbicide being sprayed by farmers. They cropdust here. It has affected our quail, butterfly, bee, wooly worm, toad/frog, firefly populations and others.
We are surrounded by farming: used to be mostly cotton, but now primarily soybeans, corn, and rice. They don’t use insecticides on these crops like they do on cotton, and I’m sure you’re right – the spraying has definitely been detrimental to many things…
I was so excited to see them! But haven’t seen them again since. I am hopeful that they will make a comeback!
Great article! Just saw my first of the summer in DC/Maryland.
I live and grew up in Southeast Michigan, and the only “lightning bugs” I remember seeing and catching growing up don’t appear until later in summer, come out at dusk, and flash a yellowish light for an hour or two. They slowly meander over lawns so they are easy to catch, and when they light up they glow for a 2-3 seconds. The past few years I have noticed a different kind of firefly that seems to stay around the tall grass in the field behind my house. These fireflies appear to fly faster than the ones I have always been familiar with, have quicker flashes of a whiter light, and fly around and flash for hours into the late night. I didn’t even realize there was more than one type of firefly because I don’t remember ever seeing any other than the slow flying, yellowish, long-flash fireflies.
North Western New York near Lake Ontario. The fireflies have been fabulous this year. Started about 10 days ago. Wish it lasted longer.
Yes, all that hot, muggy weather. Apparently, they love it!
I live in Grand Rapids, Michigan, and the firefly’s have finally appeared the past few days, after our dry spring ended this past week with several inches of rain, and temps in the 80’s.
We’ve had them for several weeks here in Northwest Georgia.
Just noticed the fireflies in West Knoxville two nights ago. There’s been a few more every night.
Just saw them this week in North Carolina!
It seems like the fireflie population is way down.. Has anyone else noticed
Hi, Ginny, yes, we wrote an article that you might find interesting. Take a look at it here.
I live in Jersey and have been anxiously waiting for the light show. It’s the 3rd week in June and we usually have by now. I hope we get. I sure would miss watching them.
I Live in Loganville Georgia we are south east of atlanta I am an a gardening nut and have been very sad over the years as we have little to no fire flys. One of the fondest memories I have of my childhood. but this year I have seen them seen some since late april 2021. Tonight is a firefly miracle I can just look out my front window and see them everywhere the little darlings are putting quite a light show. 6/18/21
In Pittsburgh, I haven’t seen any fireflies yet. I keep looking every night. They are usually out by early June. Nobody in this area has seen many, most say they have seen very few or none.
Checking in and Central Illinois and I’ve seen exactly three fireflies but I’m so excited because my grandson is three he’s live in California is whole life he’s never seen a firefly so we are patiently waiting well maybe not so patiently LOL
My backyard and woods were full of fireflies 2am in Chester NJ
Spotted a firefly in the backyard (Minneapolis) today! It’s been years. Made my heart happy!
Jenn in Asheville NC. We’ve seen exactly 2. Most weeks still in the 70s and cooler still. Strange year. I’m beginning to worry about our little guys.
Great article! Reporting from southwest Michigan, no fireflies yet, but we are supposed to be unseasonably warm this week (upper 80’s) so I’m hopeful! My twin girls think it’s the most magical time of the year, to go out and see the fireflies. They say it makes our yard and garden look like Pixie Hollow from the Disney movies about fairies (Tinkerbell, etc). 🙂
Yep, I’m in Southeast MI. Can’t wait! Even in my 50s, seeing them is always humbling and awesome.
southeast michigan here, my trees are lit up tonight!
Wow such great info, thanks for sharing.
Sadly I have not seen any in NC yet.
In central NC, I have seen fire flies the last 2 evenings. My puppy loves trying to catch them in field. Lol
I’ve just moved to middle Tennessee from east Texas and standing on my porch for a few minutes, I saw the most fireflies I’ve ever seen in my entire life. We might see a few every now and then but this was hundreds if not a thousand across the pasture. Today is May 15, 2021
I lived in Elizabethton, TN in 2001 and I too saw more fireflies there than anywhere I’ve ever lived!
I’m thinking all the NC fireflies might have moved to TN
Yes I have seen firefly since yesterday morning at 3:30 started here on May 4th
Our Mississippi homestead has the synchronous fireflies so we created a viewing area for the public
Here in Southeastern, PA, the fireflies have emerged since Tuesday night on April 27, 2021. Tonight, Wednesday, April 28, 2021 more have emerged because of the unseasonably warm weather. Although, the humidity is quite low and from what I’ve read, fireflies prefer the hot, humid nights. These beauties usually arrive in mid-June around here. We’ve also had Swallowtail butterflies arrive way too early. Hmmmm!
Wow, that’s early for PA! Thanks for sharing!
Lots of fireflies out tonight. April 13, eastern Ky
Here in west TN as well! Was not even a warm night.
I’ve enjoyed watching fireflies in the upper boughs of my backyard trees the last three nights. Yellow flashes. I’m in Richmond Virginia near the James River.b be
I saw them in Richmond too last night,, April 18! I was shocked to see them so early!
It seems very early this year, doesn’t it! Thanks for commenting.