Brood III
17-year cycle · last emerged 2014
2031
next emergence ·
States: IA, IL, MO
Iowan Brood; centered on Iowa with adjacent Illinois and Missouri.
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
Brood XXII (13-year)2027Brood XXIII (13-year)2028Brood I (17-year)2029Brood II (17-year)2030Brood IV (17-year)2032
Emergence years are well-established; the exact week varies with spring soil temperature. How this works.