NOTE: A live special answering questions surrounding the 2024 cicada emergence will appear live in the player above beginning at 6:30 p.m. CT. Watch live right here or on the NBC Chicago 24/7 streaming channel.
As experts predict the historic 2024 cicada emergence will be in full force very soon, many are wondering: how long will it last?
It's an emergence that hasn't been seen in centuries, but the length of time depends largely on the life cycle of the cicadas.
The historic 2024 emergence will see two broods of cicadas emerging simultaneously.
"This is like the year for Illinois," cicada expert Catherine Dana, an affiliate with the Illinois Natural History Survey, told NBC Chicago. "We are going to have cicadas emerging all over the state."
The two emerging broods are Brood XIII and Brood XIX, which haven't emerged together in 221 years.
Here's a timeline of what to expect:
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When the cicada emergence will begin
According to experts, the real cicada peak has yet to arrive.
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"The periodical cicadas will start emerging when the soil temperature eight inches below the ground gets to 64 degrees," Jennifer Rydzewski, an ecologist with the Forest Preserve District of DuPage County, told NBC Chicago.
The Forest Preserve District of DuPage County posted a picture on Facebook Monday, showing cicada shells hanging from a fence at an area under construction at the Willowbrook Forest Preserve in Glen Ellyn. The shells are the first sign of the cicadas' arrival.
"I am guessing because this black fencing is radiating the heat onto the bare soil…It's getting a little bit warmer down in this area, which is why we are seeing a little patch of these cicadas emerging right here," Rydzewski said, noting that other locations will likely see stronger emergences "within the next few days."
Meanwhile, several reports of cicadas sprouting from the ground have surfaced in recent days, and photos on social media showed trees covered in cicadas in parts of Illinois.
"It's getting really close," Rydzewski said.
When the cicada emergence will peak
The emergence has started earlier than average in Illinois, but much of the region has yet to see the swarms of cicadas being warned about and the defeaning sounds that have sparked 911 calls in some states.
According to some experts, the emergence of the first cicadas came about two weeks ahead of the historic average. It will continue to be sporadic, however, as soil temperature, mulch and turf grass all impact cicadas differently. For example, the soil is warmer near pavement, so cicadas in the those spots are expected to emerge quicker.
Experts with the Insect Asylum estimated peak emergence would arrive in mid-May for the Chicago area.
The ideal soil temperature for cicadas is 64 degrees, but a rise in humidity levels can also play a role, the Insect Asylum reported.
"Research shows that the particular night of the periodical cicadas’ emergence depends on soil temperature," a post from the National Weather Service said. "Cicada juveniles, or nymphs, emerge after a rainstorm when the soil temperature at 8 inches in depth exceeds approximately 64°F."
What happens once cicadas emerge
When cicada nymphs first come out from the ground, they climb up to a tree or another high place and shed their shells.
In a year of full emergence, after the bugs surface, they then begin mating, which is often met with the noise most associate with cicadas. Experts with the DuPage Forest Preserves said it takes about a week from emergence before cicadas begin mating.
See a video explanation of their life cycle below:
How long the emergence will last
Cicadas have a lifespan of approximately four weeks, meaning the emergence is set to last through at least mid-June.
Where the emergence will be seen
For the Chicago area, Brood XIII will be most seen in parts of northern Illinois and Indiana, and possibly even in Wisconsin and Ohio, Dr. Gene Kritsky, dean of Behavioral and Natural Sciences at Mount St. Joseph University in Cincinnati, said.
The Northern Illinois Brood itself is huge, with a reputation for the "largest emergence of cicadas anywhere," according to the University of Illinois.
Meanwhile, Brood XIX, or the Great Southern Brood cicadas, have a more widespread population, covering parts of Missouri, Illinois, Louisiana, North Carolina, Virginia and Maryland.
"Brood XIX is arguably the largest (by geographic extent) of all periodical cicada broods, with records along the east coast from Maryland to Georgia and in the Midwest from Iowa to Oklahoma," the University of Connecticut reports. "Although 13-year cicadas are generally considered to have a southern distribution, the northernmost known record of this brood is in Chebanse, IL, roughly 75 miles from Chicago’s Loop."
Across most of Illinois and the Chicago area at least one of the two broods is likely to emerge, but in a narrow part of the state, both could emerge at the same time, in the same place.
"Somewhere around Central Illinois, probably like around Springfield, is what some researchers are predicting we may see some overlap of these two ... different broods," Dana said. "It's not going to be a large area. But there will likely actually be some mating happening between these two broods, which is going to be really exciting."
Here's a map of what to expect in Illinois, according to data from the USDA Forest Service.
