This year, the autumnal equinox takes place on Friday, September 22.
You may have noticed that the days have been getting shorter, and the nights have been drawing in.
That’s because today is the Autumnal Equinox – which officially marks the end of summer in the Northern Hemisphere.
An equinox occurs when the sun passes directly over the Earth’s equator, resulting in a day and night that equal in length.
There are two equinoxes every year – one around March 22 and one around September 22.
In the southern hemisphere the seasons are flipped, and the September equinox marks the start of spring.