National Phenology Network – “Status of Spring – 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”? Spring leaf out continues to spread up the country, three to four weeks earlier than a long-term average (1981-2010) in some locations. Boston, MA is 23 days early, Pittsburgh, PA is 8 days early, and Kansas City, MO is 5 days early.
Spring leaf out has also arrived in parts of the West. Spring leaf out is on time to 2 days late in San Diego, LA, and San Francisco, CA and 10 days early in Portland, OR and Seattle, WA. Parts of the Columbia Plateau are 30 days early.Spring bloom has also arrived in several Southeast and Southwest states. Spring bloom is between 1 day and 3 weeks early. Check back on this page throughout the spring for updates on when spring arrived and whether spring was early or late for your location.