Map: Spring Leave Anomaly as of February 21, 2017

In 2017, we see very large anomalies in the southeastern United States on the Spring Leaf Index map, where the Index was met up to three weeks earlier than what is typical for these locations. 

The timing of leaf-out, migration, flowering and other seasonal phenomena in many species is closely tied to local weather conditions and broad climatic patterns. The Spring Index maps and Accumulated Growing Degree Day Maps offered by USA-NPN shed light on plant and animal phenology, based on local weather and climate conditions.