- Festival of Birds at Detroit Lakes, MN is in mid-May.
- Heaviest migration period of the year. Spotted and Semi-palmated Sandpipers, Semi-palmated Plovers, American Bittern, Least and Great-crested Fycatchers, Eastern Kingbird, Gray-cheeked and Wood Thrushes, Eastern Towhee, Gray Catbirds, Black-billed Cuckoos, Common Nighthawks, Eastern Wood-Pewee, Red-eyed and Warbling Vireos, Common Yellowthroat, Tennessee, Nashville, Golden-winged, Northern Parula, Black-throated Green, Black and White, Chestnut-sided, Blackpoll, and Yellow Warblers, American Redstarts, Scarlet Tanagers, Sedge and Marsh Wrens, Ovenbirds, Bobolinks, Rose-breasted Grosbeaks, Clay-colored Grasshopper, Savannah and Harris' Sparrows and Indigo Buntings arrive.
- Purple Finches are leaving for the north.
- Summer Tanagers may show up.
- Wild Turkeys' eggs are hatching.
- Ruby-throated Hummingbirds and Baltimore Orioles are back.
- Eta Aquarids meteor shower is early-May.
- International Migratory Bird Day is mid-May.