There have been no shortage of cicada sightings across the Chicago area as the emergence begins in force, but there could be more coming thanks to storms Monday.
The stormy weather brought with it a rise in humidity levels, which were one of the factors involved in triggering cicadas' emergence from underground, according to the Insect Asylum.
As of Monday morning, NBC 5 Storm Team meteorologists said dew points were set to climb into the low-to-mid 60s, up from the 50s over the weekend. They'll likely stay at that level again Tuesday.
The emergence was expected to be sporadic in the Chicago area as many waited for soil temperatures to warm.
Warm weekend temperatures already sparked an increase in sightings across the Chicago area, as experts said the emergence would begin in force once the ground reached 64 degrees.
According to some experts, the emergence started about two weeks ahead of the historic average. It will continue to be sporadic, however, as soil temperature, mulch, turf grass and humidity all impact cicadas differently. For example, the soil is warmer near pavement, so cicadas in the those spots are expected to emerge quicker.
A map that tracks cicada sightings across the U.S. shows some of the highest reports have been in suburbs west of Chicago, particularly near the Downers Grove area. The Oak Park area has also seen a higher number of sightings as well as some southern suburbs around the Palos Park and Park Forest areas and northern suburbs like Lake Forest and Highland Park.
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The map from Cicada Safari, an app created by Dr. Gene Kritsky at Mount St. Joseph University in Cincinnati to track cicadas, allows residents and experts to submit photos of cicada sightings in their area. Once those images are verified by experts, the sighting is marked on the map.
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A high number of sightings have also been reported in areas of central and southern Illinois, where the emergence began earlier than much of the Chicago area. Still, it appears the Chicago area and northern Illinois have the highest number of reports in the state.
Kritsky noted he traveled to Illinois last week and over the weekend and found a particularly notable emergence in Charleston, Illinois, south of Champaign.
"They were having the beginnings of a really big emergence," he said. "We got there at noon and hundreds had emerged just that morning and were still finishing the process of transitioning."
Still, elsewhere in the U.S., areas around Tennessee and Kentucky, as well as North Carolina and South Carolina, have seen higher numbers so far. That's not unexpected, however, given their season started earlier due to warmer climates.
The data for the map is limited to the submissions it receives. Kritsky said that, as of Monday, at least 40,000 submissions had been received for this year's emergence so far.
"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 current emergence involves two broods of cicadas - Brood XIII and Brood XIX - emerging simultaneously, which they haven't done in more than 220 years.
Cicadas have a lifespan of approximately four weeks, meaning the emergence is set to last through at least mid-June.
