Hummingbirds in Pennsylvania, primarily Ruby-throated Hummingbirds, generally leave for their southward migration by the end of August or early September. By mid-September, almost all hummingbirds have typically left Pennsylvania. Some stragglers may still pass through toward the end of September, especially those migrating from further north. It's recommended to keep hummingbird feeders up until no hummingbirds have been seen for two weeks to support their energy needs during migration.
Summary of Hummingbird Departure in PA
- Most hummingbirds leave by the end of August or early September.
- Almost all hummingbirds are gone by mid-September.
- Some late migrants may be seen until late September.
- Feeders should be kept up until no hummingbirds are seen for two weeks after the last sighting to aid their migration.
This timing corresponds with changes in daylight, food availability (flowers and insects), and temperature that trigger their migration instinct.
