Based on 1,756 research-grade iNaturalist observations in Delaware, Monarch is most often recorded in August; in Delaware it behaves like a summer visitor / breeder. It ranks #1 among butterflies recorded in the state in our data.
Danaus plexippus
Monarch in Delaware 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 Delaware in August
Eastern Tiger Swallowtail
Huron Skipper
Zabulon Skipper
Spicebush Swallowtail
Silver-spotted Skipper
Common Buckeye
Variegated Fritillary
Red-banded Hairstreak
Places to look in Delaware
State ParkCape Henlopen State Park
Botanical GardenWinterthur Museum, Garden and Library
State ParkTrap Pond State Park
State ParkKillens Pond State Park
State ParkBellevue State Park
State ParkBrandywine Creek State Park
FAQ
When does Monarch appear in Delaware?
Mainly July–September, with the most records in August.
How common is Monarch in Delaware?
It ranks #1 by number of iNaturalist observations among butterflies in Delaware (1,756 records in our sample).