Cicadas. A 13 year brood and a 17 year brood are set to both emerge at the same time this year. This hasn't happened since Jefferson was president. They estimate that over a trillion of them will be out singing all at the same time. Here's a map of where the main emergences will be. The way I read it, the broods won't overlap to give a double number in any one area. They will be in adjacent areas so they'll be doubly wide spread.
When the soil reaches 64F, they'll be along directly.