Stanley Kunitz - End of Summer

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
Amaded, 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 forever over.

Already the iron door of the North
Clangs open: birds,leaves,snows
Order their populations forth,
And a cruel wind blows.

Stanley Kunitz

http://www.poemhunter.com/poem/end-of-summer/