Based on 10,657 research-grade iNaturalist observations in Pennsylvania, Eastern Tiger Swallowtail is most often recorded in July; in Pennsylvania it behaves like a summer visitor / breeder. It ranks #2 among butterflies recorded in the state in our data.
Papilio glaucus
Eastern Tiger Swallowtail in Pennsylvania 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 Pennsylvania in July
Monarch
Silver-spotted Skipper
Spicebush Swallowtail
Great Spangled Fritillary
Small White
Huron Skipper
Red Admiral
Black Swallowtail
Places to look in Pennsylvania
National ForestAllegheny National Forest
State ParkPresque Isle State Park
Botanical GardenJenkins Arboretum
State ParkCherry Springs State Park
State ParkColton Point State Park
State ParkLeonard Harrison State Park
FAQ
When does Eastern Tiger Swallowtail appear in Pennsylvania?
Mainly July–August, with the most records in July.
How common is Eastern Tiger Swallowtail in Pennsylvania?
It ranks #2 by number of iNaturalist observations among butterflies in Pennsylvania (10,657 records in our sample).