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Autumnal Equinox – Fall Equinox

Equinoxes are opposite on either side of the equator, so the autumnal (fall) equinox in the Northern Hemisphere is the spring (vernal) equinox in the Southern Hemisphere and vice versa.

Illustration image
Fall is called autumn in many countries.
©bigstockphoto.com/Subbotina Anna

When is the equinox in my city?

Fall equinox, Southern Hemisphere

March equinox 2015:
March 20, at 22:45 UTC

(Australia, New Zealand, South America, Southern Africa)

Fall equinox, Northern Hemisphere:

September equinox 2015:
September 23, at 08:20 UTC

(USA & Central America, Asia, Canada, Europe, Northern Africa)

Not entirely equal day & night

On the two equinoxes every year the sun shines directly on the equator and the length of day and night is nearly equal – but not exactly.

Equinox the first day of fall?

In the northern hemisphere, the fall equinox marks the first day of fall (autumn) in what we call astronomical seasons. There's also another, more common definition of when the seasons start, namely meteorological definitions, which are based on average temperatures rather that astronomical events.

Topics: Astronomy, Sun, Earth, Seasons, September, March


Solstices & equinoxes

  1. Spring / Vernal equinox
  2. Summer solstice
  3. Autumnal / Fall equinox
  4. Winter solstice
  5. Equal day & night?
  6. Seasons: Astronomical vs Meterological

Equinox & Solstice in Culture

Sunrise & Sunset times

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