Many of us are greeted annually by the buzz and chirp of the "Dog Day Cicada", which usually visits in July and hangs out for a few weeks, mates, and then dies off only to revisit the following summer. Every so often, a brood of cicadas emerges out of the ground and provides a much larger feeding frenzy for birds and mating frenzy for fellow periodical cicadas.
This year is one of those years. Brood II (there are fifteen broods of periodical cicadas) is poised to awaken when ground temperatures reach 64 degrees, which is likely to occur in late May into early June. How early depends on warmth and soil moisture but that range is the typical "magic timeframe" for temperatures to reach that mark at a consistent enough level. The last big "brood" of cicadas to buzz around the East Coast was Brood X, which appeared in 2004 and is now slumbering underground until 2021.
The brood's range extends generally through the Piedmont from the Carolinas north into New York State, which its greatest concentration over the Mid Atlantic and New York metro. Yay us! (sarcasm intended)
Cicadas often emerge at night from underground, burrowing themselves out of the ground, molting their exoskeletons and then hanging out in trees with the buzzing sound during the day, chirping sound at night. Some areas see larger concentrations of them emerging out of the ground than others, with those larger concentrated areas sometimes seeing damage to vegetation (female cicadas slice holes in tree branches to lay their eggs).
The weather-related part of this post is the temperature in the soil -- consistency in temperatures at or above 64 a few feet underneath the surface of the ground (where they slumber) is critical to lead to the emergence of the buzzing cicadas.
Believe it or not, there's a website dedicated to this stuff...and if you want all sorts of cicada info on the periodical cicada, it's worth checking out.