Brood XXIII

13-year cycle · last emerged 2015

States: AR, IL, IN, KY, LA, MO, MS, TN

Lower Mississippi River Valley Brood.

Source: USDA Forest Service / UConn. Adults emerge when soil 20 cm down reaches ~18°C (64°F), usually mid-to-late spring.

Next broods to emerge

Emergence years are well-established; the exact week varies with spring soil temperature. How this works.