INDIANA, USA — Cicadas emerge once ground temperatures warm up, especially after heavy rainstorms. According to the National Weather Service in Chicago, once soil temperatures eight inches deep hit 64 to 65 degrees, cicada juveniles will start emerging. Because of heavy spring rains helping to warm ground temperatures, the cicadas may be able to emerge faster this spring.
Tap HERE to track soil temperatures from Purdue University.
Insects are warm-blooded, which means they can develop and emerge faster in the warmer weather. This includes cicadas as well. Generally we can expect cicadas in the southern Great Lakes to emerge in mid May through June. However with generally warmer winter temperatures, and very heavy April rains, the cicadas may emerge slightly faster, but dependent on the brood and location.
Two broods will emerge this year | Where in Indiana?
It is rare for two broods to emerge at the same time. According to the University of Connecticut this is the first time:
- since 2015 a 13-year brood and a 17-year brood will emerge in the same year
- since 1803 that Brood XIII and Brood XIX will emerge in the same year
Brood XIII (17-year brood) will emerge in northwest Indiana and much of Illinois. Indiana counties included are Lake, Porter and LaPorte.
Brood XIX (13-year brood) will emerge in western and southwestern Indiana and southern Illinois. Indiana counties included are Gibson, Knox, Posey, Sullivan, Vanderburgh, Vigo, and Warrick.
How are 8" deep soil temperatures now?
Indiana has quickly warmed deep soil temperatures mainly in to the mid-and-upper 50s. There is a report near Vincennes of 62 degrees. All these temperatures are from Purdue Mesonet.
Cicadas generally start emerging with soil temperatures near 64.5 degrees Fahrenheit.
There is not much data on averages for soil temperatures in Indiana for specific locations, however we are quickly warming up temperatures a bit faster than normal thanks to warmer weather and lots of rainfall. Spring rains help to thaw out the ground from winter.
For April, most of central and southwestern Indiana have picked up above-average rainfall, leading to warmer ground temperatures.
When will the cicadas emerge this year?
Weather forecasting is hard enough. Trying to forecast insect behavior is even tougher. However the brood in SW Indiana may emerge faster. Generally, expect late-April through late May for emerging (compared to mid-May through mid June). The brood in NW Indiana can be expected to emerge in early May through early June (compared to mid May through late June).
- Brood XIII (NW Indiana): generally mid-May
- Brood XIX (SW Indiana): generally early May (maybe some very late April if warm temperatures keep coming)
Once they start emerging, expect the cicadas to live for 5-6 weeks.
What about the rest of Indiana?
2024 will only bring cicadas to extreme NW Indiana and SW Indiana. The rest of the state has Brood X which last emerged in 2021. The next time they will come out will be 2038.
— 13News Meteorologist Matt Standridge