An agitation of the air,
A perturbation of the light
Admonished me the unloved year
Would turn on its hinge that night.
I stood in the disenchanted field
Amid the stubble and the stones,
Amazed, while a small worm lisped to me
The song of my marrow-bones.
Blue poured into summer blue,
A hawk broke from his cloudless tower,
The roof of the silo blazed, and I knew
That part of my life was over.
Already the iron door of the north
Clangs open: birds, leaves, snows
Order their populations forth,
Kunitz explains that summer is over and a new season is approaching and a new stage of his life is beginning. Whether this is simply referring to a change in season, or a change in one’s life is up to the interpretation of the reader. 

End of Summer