The autumnal equinox, which marks the first day of fall for the Northern Hemisphere, is set to officially begin Thursday, Sept. 22, at exactly 10:21 a.m. EDT. The day marks the official end of summer, and will have roughly an equal amount of nighttime and daytime.

The word equinox comes from aequus, the Latin word for "equal," and nox, the Latin word for "night." This word hints at the fact that during the equinox, the sun crosses the so-called "celestial equator," an imaginary line over the Earth's equator, which brings an equal amount of daylight and darkness. The autumnal equinox occurs in September every year, most often on the 22nd, 23rd or 24th. 

In the Southern Hemisphere, the September Equinox marks the first day of spring, which is called the Vernal Equinox.

Here are some of the quotes collected from Goodreads and Quote Garden:

  • “Autumn wins you best by this, its mute / Appeal to sympathy for its decay.” ― Robert Browning
  • “Autumn is a second spring when every leaf is a flower.” ― Albert Camus
  • “Autumn is the hardest season. The leaves are all falling, and they're falling like they're falling in love with the ground.” ― Andrea Gibson
  • “Autumn carries more gold in its pocket than all the other seasons.” ― Jim Bishop
  • "Life starts all over again when it gets crisp in the fall." —F. Scott Fitzgerald, The Great Gatsby
  • "Designers want me to dress like Spring, in billowing things. I don't feel like Spring. I feel like a warm red Autumn." —Marilyn Monroe
  • "Autumn seemed to arrive suddenly that year. The morning of the first September was crisp and golden as an apple." —J.K. Rowling, Harry Potter and the Deathly Hallows
  • "I'm so glad I live in a world where there are Octobers." — L.M. Montgomery, Anne of Green Gables
  • "Aprils have never meant much to me, autumns seem that season of beginning, spring." — Truman Capote, Breakfast at Tiffany's
  • “There is something incredibly nostalgic and significant about the annual cascade of autumn leaves.” ― Joe L. Wheeler
  • “Wild is the music of autumnal winds / Amongst the faded woods.” ― William Wordsworth
  • “Autumn's the mellow time.” ― William Allingham
  • “It’s fall coming, I thought, I can smell that sour-molasses smell of silage, clanging the air like a bell – smell like somebody’s been burning oak leaves, left them to smolder overnight because they’re too green.” ― Ken Kesey
  • “I loved autumn, the one season of the year that God seemed to have put there just for the beauty of it.” ― Lee Maynard
  • "There is a harmony in autumn, and a lustre in its sky, which through the summer is not heard or seen, as if it could not be, as if it had not been!" ― Percy Bysshe Shelley