The Autumn Equinox took place on Monday, September 23, with the precise moment of equinox, when the sun was directly over the Earth’s equator, at 8.50am BST.
How is the start of fall season celebrated?
Hundreds of brave Brits stripped off to take part in a huge skinny-dipping session in the chilly North Sea on Sunday, September 22.
The event, which takes place every year in Druridge Bay, Northumberland, marks one of the two days of the year on which the sun’s path exactly follows the equator, and raises money for mental health charity MIND.
Jax Higginson, who organises the annual event, now in its eighth year, said: “It was massive and brilliant. There was a lot of joy and passion on the beach this morning.
“It’s not just about taking our clothes off it’s about taking a risk, connecting with nature, celebrating life and embracing our own bodies.
“It always happens around the Autumn Equinox and that’s intentional. It’s my way of saying thanks for the summer and finding a way to make the transition to winter.
“People were splashing about and there was screams and laughter, it was gorgeous. It makes it all feel worthwhile.
“I think it was the warmest it has ever been.”
The fundraiser coincided with the last of glorious summer weather, allowing many Brits to enjoy one final BBQ in sunshine, before chillier autumnal temperatures sweep in.
For some, the equinox is a spiritual time, with druids and pagans particularly keen on the astronomical event.
In pagan beliefs the equinox is also know as Mabon, Second Harvest or Alban Elfed which marks a time of thanksgiving for the harvest.
New-age, spiritual people will spend the morning at Stonehenge, where they will watch the sun rise on a new season.
In some rural communities, it is traditional to drink dandelion and burdock cordials on the day of the equinox to cleanse the body and prepare for autumn.
Others will celebrate by trying to balance an egg, thanks to the untrue urban legend that the equinox is the only day when egg balancing is possible.
When is the autumn equinox in 2019?
This year the autumn equinox in the northern hemisphere took place on September 23 – the same day as the beginning of astronomical autumn.
The autumn equinox marks the day when the northern hemisphere slightly tilts away from the sun, meaning days become shorter and the temperature begins to cool.
It is the day when daylight hours and night-times are of equal length.
This carries on until the winter solstice when the northern hemisphere begins to tip back towards the sun on its axis.
When does autumn officially start?
For astronomers, the equinox marks the end of summer and the start of autumn, meaning fall has officially fallen.
So in 2019 autumn starts on September 23.
The end of autumn officially falls on December 21.
Meteorologists, meanwhile, prefer to divide the year a bit differently, with autumn taking place from September 1 to the end of November.
Whichever one you use, we’re officially in autumn now, so dig out your coats and put that BBQ away for another year.