Image caption
Graph showing how much cooler or warmer than average it was in Pittsburgh, PA in March 2025. The graph also marks the date when the first signs of spring appear (also known as 'first leaf' or 'leaf out') on average (March 25), as well as when it occurred this year (March 17). Warmer than average temperatures led to spring leaf out arriving as much as eight days early. To check on the arrival of spring at a different location, visit the USA National Phenology Network's visualization tool.