Spring triggers the northward migration of 5 billion birds from Neotropical regions (e.g., ruby-throated hummingbirds arriving in the Gulf Coast by late February). Groundhog emergence (February 2) is a cultural, not biological, marker; actual emergence of true hibernators like the woodchuck depends on local soil temperature exceeding 40°F (4°C).
The USA National Phenology Network tracks “spring index” models. Across CONUS, first leaf-out of lilacs and honeysuckles has shifted earlier by an average of 9.5 days since 1981. In Washington, D.C., the famous cherry blossoms (Prunus serrulata) now reach peak bloom approximately 6 days earlier than in the 1920s. spring season usa
[Generated for Academic Use] Date: April 14, 2026 Spring triggers the northward migration of 5 billion
Spring arrives earliest here, often beginning in late February. Characterized by rapid warming and high humidity, the Southeast experiences “green-up” by early March. However, this region is also prone to late-season freezes (e.g., the 2017 March freeze that destroyed 40% of Georgia’s peach crop), creating agricultural risk despite the early start. Across CONUS, first leaf-out of lilacs and honeysuckles