Based on 3,225 research-grade iNaturalist observations in Ohio, Hackberry Emperor is most often recorded in August; in Ohio it behaves like a summer visitor / breeder. It ranks #16 among butterflies recorded in the state in our data.
Asterocampa celtis
Hackberry Emperor in Ohio 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 Ohio in August

Monarch

Eastern Tiger Swallowtail

Zabulon Skipper

Silver-spotted Skipper

Pearl Crescent

Black Swallowtail

Peck's Skipper

Spicebush Swallowtail
Places to look in Ohio
Cincinnati Zoo and Botanical Garden
Chadwick Arboretum
Wayne National Forest
Cox Arboretum and Gardens MetroPark
Hocking Hills State Park
Maumee Bay State Park
FAQ
When does Hackberry Emperor appear in Ohio?
Mainly June–August, with the most records in August.
How common is Hackberry Emperor in Ohio?
It ranks #16 by number of iNaturalist observations among butterflies in Ohio (3,225 records in our sample).