Based on 1,764 research-grade iNaturalist observations in Wisconsin, Trumpeter Swan is most often recorded in June; in Wisconsin it behaves like a seasonal. It ranks #36 among birds recorded in the state in our data.
Cygnus buccinator
Trumpeter Swan in Wisconsin by month
Bars show research-grade observations per month. They mix true seasonality with how often people are outdoors, so treat small numbers with caution.
Also seen in Wisconsin in June
Red-winged Blackbird

American Robin

Mallard
Sandhill Crane
Canada Goose

Great Blue Heron

Wild Turkey

House Sparrow
Places to look in Wisconsin
Aztalan State Park
Wyalusing State Park
Chequamegon–Nicolet National Forest
Merrick State Park
Perrot State Park
Lake Kegonsa State Park
FAQ
When does Trumpeter Swan appear in Wisconsin?
Mainly February–November, with the most records in June.
How common is Trumpeter Swan in Wisconsin?
It ranks #36 by number of iNaturalist observations among birds in Wisconsin (1,764 records in our sample).