How do you know when spring has begun? Is it the appearance of the first tiny leaves on the trees, or the first crocus plants peeping through the snow? The First Leaf and First Bloom Indices are synthetic measures of these early season events in plants, based on recent temperature conditions. These models allow us to track the progression of spring onset across the country.
How does this spring compare to “normal”?
January 23, 2023
Spring leaf out conditions have arrived in southern states. Spring is up to three weeks earlier than average (the period of 1991-2020) in parts of Texas, Arkansas, Louisiana, Mississippi, Alabama, Georgia, and South Carolina. Austin, TX is 9 days early, Jackson, MS is 12 days early, and Charleston, SC is 10 days early. In central Florida, spring is 1-2 days later than average.
Spring bloom has also arrived in the southernmost parts of Texas and Florida. Spring bloom is 8-12 days early in Texas and on time to a few days early in Florida.
When will spring arrive at your location? Check back on this page, we will update it frequently as spring progresses across the country!
Download the maps in KML/KMZ and other formats via our Geoserver Request Builder Tool. Download static .png maps of leaf and bloom.
How often do we see a spring this early or late?
How typical is this year’s spring? Darker colors represent springs that are unusually early or late in the long-term record. Gray indicates an average spring.
Check back on this page to see how spring unfolds this year!
When did spring arrive at locations across the country?
The First Leaf Index map at right shows locations that have reached the requirements for the Spring Leaf Index model so far this year.
The First Bloom Index map at right shows locations that have reached the requirements for the First Bloom Index model.
Learn more about the Extended Spring Indices and the data products available.
USA-NPN also produces a suite of Accumulated Growing Degree Day map products.
What is behind these maps?
The Extended Spring Indices are mathematical models that predict the “start of spring” (timing of leaf out or bloom for species active in early spring) at a particular location (Schwartz 1997, Schwartz et al. 2006, Schwartz et al. 2013). These models were constructed using historical ground-baesd observations of the timing of first leaf and first bloom in a cloned lilac cultiv
