When Do Cicadas Come Out 2025 Illinois. Two groups of periodical cicadas, brood xiii and xix, will emerge together in 2025 for the first time since 1803. Millions of the loud, large insects.
Find out when, where, and how to observe, protect, and eat these crunchy insects. Illinois will witness the emergence of two massive broods of cicadas in 2025, brood xiii and brood xix, which could bring billions of insects to the surface.