The Autumn Equinox, when the day and night are in balance, is on Friday September 23. Celebrations are taking place over the next week or so. Here's a listing of pagan and witchy events in or near London, because that's where I live, but I also a few festivals further afield and plenty of things online that you can enjoy anywhere.
51.582208, -0.141830 at 5pm. Tickets free but you must reserve a place. https://www.meetup.com/LondonWoodlandWitches/
Please note: I am not responsible for any of these events except my candle magic and poppet workshops at London Month of the Dead. I try to make sure all details are correct, but contact the organisers of any event you are interested in for more information before turning up. If you know of something you want listed, please email the details to me at firstname.lastname@example.org.