Could cold snap delay cicadas' emergence in Illinois?

CHICAGO (CBS) -- Nature enthusiasts have been eagerly awaiting this year's historic arrival of periodical cicadas.

In the Chicago area, the emerging cicada brood comes every 17 years, while downstate, a different brood is emerging that comes every 13 years. This is the first time both broods have emerged together since 1803, numerous reports point out.

For most of their lives, cicadas live underground and emerge once the soil reaches 64 degrees. 

The expectation has been that they will appear sometime in May or early June, according to Ken Johnson, a horticulture educator at the University of Illinois.

In Missouri, the ground has reached 64 degrees 8 inches below the surface – perfect conditions for the cicadas to start emerging.

But in some states, an incoming cold snap could delay their arrival and put everything behind schedule.

Could Illinois be one of those states? CBS 2 asked an entomologist, and Chief Meteorologist Albert Ramon, about the weather impact.

According to state data, the soil temperature was about 53 degrees as of Thursday, April 18. With a frost in the forecast this weekend, it could affect the anticipated emergence in late May or early June.