Based on 3,086 research-grade iNaturalist observations in Illinois, Green Heron is most often recorded in May; in Illinois it behaves like a summer visitor / breeder. It ranks #45 among birds recorded in the state in our data.
Butorides virescens
Green Heron in Illinois 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 Illinois in May
Red-winged Blackbird
American Robin
Canada Goose
Mallard
Baltimore Oriole
House Sparrow
Northern Cardinal
Gray Catbird
Places to look in Illinois
State ParkCahokia
Botanical GardenMorton Arboretum
National ForestShawnee National Forest
Botanical GardenChicago Botanic Garden
Botanical GardenLadd Arboretum
State ParkStarved Rock State Park
FAQ
When does Green Heron appear in Illinois?
Mainly April–September, with the most records in May.
How common is Green Heron in Illinois?
It ranks #45 by number of iNaturalist observations among birds in Illinois (3,086 records in our sample).