CHESTERFIELD, Mo. – Brood XIX, the 13-year periodical cicadas, are now reaching potentially dangerous sound levels in the St. Louis area.

A FOX 2 crew set out with a decibel meter Tuesday to find out just how noisy our visitors really are. It’s been discovered that our loudest everyday noises now have company.

We put the meter in a cicada-laden tree at Faust Park in Chesterfield and consistently tracked decibel (dBA) readings in the high 80s to mid-90s, with a high of 94+ dBA. 

Experts say prolonged exposure of 30 minutes or more at that level can lead to permanent hearing loss.

The bugs were much louder than the ornate fountain at Delmar Gardens off of U.S. Interstate 64, passing the levels of a tanker truck on the interstate, and louder than an arriving MetroLink train at UMSL. 

A riding lawnmower in Chesterfield was louder but only when it passed close by the meter. The man riding the mower said he could still hear the cicadas.

“They’re pretty bad,” Jeff Presson said, seated on the mower in a hooded sweatshirt on a 90+ degree day. “Earlier, when we were cutting, I probably had about 50 of them on me. They’d be up on my head. That’s why I’m wearing the hoodie.”

Cicadas swarm St. Louis – You have questions. We have answers.

The piercing sounds punctuated a class outing for graduating St. Gerard 8th graders at Faust Park. Their families have been running into the same ‘behavioral’ issues we’ve been seeing.  

“They divebomb,” Susie Kalinowski, mother of a graduate, said. “Everywhere you go in my house, you hear (them)… all the windows closed, air conditioning on, dogs barking, children running around—you hear them!”

One of the world’s leading cicada experts, Dr. Gene Kritsky, a biologist at Mount St. Joseph University in Cincinnati, told FOX 2 the loudest cicadas he’d ever measured hit 96 decibels. 

“These insects got me tenured,” he laughed. 

St. Louis probably wouldn’t be hearing the din for too much longer, Krtisky said.

“It’s been about two weeks (since they started singing in St. Louis),” he said. “It’s reaching the peak and then in another week, there will still be singing but it won’t be as loud. It will start to decline. Then, when the signing is done, they’re done.”

For now, the one thing we’ve found to be far louder than the bugs: The St. Gerard Class of 2024, doing their best “cicada song.”

They hit 111.8 dBA on the meter.