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.
Fall equinox, Southern Hemisphere
(Australia, New Zealand, South America, Southern Africa)
Fall equinox, Northern Hemisphere:
(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.
Solstices & equinoxes
- Spring / Vernal equinox
- Summer solstice
- Autumnal / Fall equinox
- Winter solstice
- Equal day & night?
- About seasons