Cicadas are recognizable insects, primarily known for the incredibly loud, synchronized buzzing noise created by the males during the summer months. When people ask about the return of cicadas, they are often referring to two very different populations: annual cicadas, which are heard every year, and their periodical relatives. The periodical cicadas are the true spectacle that garners national attention due to their synchronized emergence. Understanding this distinction is the first step in predicting when these noisy neighbors will appear next, explaining why some years bring a noticeable hum while others unleash a massive natural event.
The Difference Between Annual and Periodical Cicadas
The two main populations of cicadas in North America follow fundamentally different life cycles. Annual cicadas, often called Dog-Day cicadas, are a larger species with distinct green and black coloration and clear wings. These insects are seen every summer, typically from late July into August. Their individual life cycles are not synchronized, meaning only a fraction of the population emerges each year. Though their life cycle can last from two to ten years, this staggered nature ensures that some adults appear annually.
In contrast, periodical cicadas belong to the genus Magicicada and are known for their unique time-keeping ability. They are smaller than annual cicadas, featuring jet-black bodies, bright red eyes, and transparent wings with orange veins. Their defining characteristic is their prime-numbered life cycles of either 13 or 17 years, which keeps their entire population in a specific region synchronized. When they emerge, they do so en masse, resulting in billions-strong swarms.
The Timing and Location of the Next Major Broods
Predicting when cicadas return depends entirely on which specific group, known as a brood, is next in the emergence schedule. The most recent large-scale event occurred in 2025 with the emergence of Brood XIV, a significant 17-year brood. This emergence covered a wide range, concentrated primarily in Kentucky and Tennessee.
The next major, widespread emergence is anticipated to be Brood XXII, which follows a 13-year cycle and is scheduled to surface in 2027. This brood is concentrated in the Southern and Midwestern United States, including states such as Ohio, Kentucky, Mississippi, and Louisiana. Each brood has a distinct geographic range, and the specific year of emergence is highly predictable.
Brood emergences begin in the spring, generally starting in late April and continuing through June, depending on latitude and local climate. Warmer, southern locations see the insects appear earlier than cooler, northern regions. The timing of these mass events is precise and occurs on a clockwork schedule. Entomologists track these regional broods by assigning them Roman numerals.
The Underground Life Cycle and Emergence Triggers
The vast majority of a periodical cicada’s life is spent beneath the soil in the nymph stage. During this prolonged subterranean period, the nymphs feed on xylem fluid—water and dilute nutrients—drawn from the roots of trees. They pass through five developmental stages, gradually growing from the size of a small ant to nearly the size of a mature adult.
The synchronized emergence is triggered by a specific environmental cue in their final year underground. Nymphs begin their ascent when the soil temperature at a depth of about eight inches reaches a consistent 64 degrees Fahrenheit. This threshold typically occurs in late spring. A warm, soaking rain can often act as the final catalyst, prompting a unified emergence.
Once they break through the soil, the nymphs climb onto vertical surfaces to undergo their final molt into the winged adult form. The adult life is extremely brief, lasting only about four to six weeks. This short period is dedicated solely to mating and, for the females, laying eggs in the branches of woody plants. The newly hatched nymphs then drop to the ground and burrow down to begin the 13- or 17-year cycle.