(WHTM) — Spring officially started on March 20, which means longer days, warmer weather, and leaves on trees starting to appear again.

But, according to the USA National Phenology Network (NPN), portions of the Midstate are seeing a very early spring.

The NPN says that portions of the Southeast, lower Midwest, mid-Atlanbtc, and New York City area are seeing either the earliest spring leaf on record or one that lasts every 40 years. However, parts of Arizona are seeing a spring that occurs this late once every 40 years, which is according to the map that can be seen here.

The NPN bases the spring leaf index on the “leaf out” of lilacs and honeysuckles, which are among the first plants to show their leaves in the spring. The index is associated with the first leafing of early spring shrubs and leafing out of deciduous trees, according to the NPN.

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A map from the National Weather Service and the NPN shows this leaf out.

You can see by the map that portions of the Midstate are either seeing their earliest spring on record or one that occurs once every 40 years.