Get ready to break out the pumpkins and horchata– fall starts this weekend! Technically, autumn officially begins at 8:54 p. m. on Saturday, Sept. 22. Saturday at 8:54PM is the official start to Fall. Fall begins during the autumnal equinox. Every year between the 21st and 23rd of September, the sun is directly over the equator, which causes the equinox. Equinox is Latin for "equal nights" because many on Earth experience 12 hours of daylight and 12 hours of nighttime on this day.