Autumn has officially arrived in the Northern Hemisphere with today’s equinox, the astronomical event that marks the balance between day and night as the sun crosses directly over the equator.
This year’s autumn equinox took place on September 22 at 16:20 local time in Greece, though it can occasionally fall on September 23. From now until the winter solstice on December 22, days will gradually shorten while nights grow longer.
In contrast, the Southern Hemisphere welcomes the opposite season, as the September equinox signals the beginning of spring there. Days will lengthen until the summer solstice in December.
The equinox occurs due to Earth’s 23.5-degree axial tilt. As the planet orbits the sun, the angle of sunlight shifts, giving rise to the seasons. On equinox days, Earth’s axis is tilted neither toward nor away from the sun, creating nearly equal daylight and darkness worldwide.
The cultural significance of the equinox stretches back thousands of years. In ancient Greece, it was closely linked to the myth of Demeter and Persephone, marking Persephone’s descent into the underworld and the arrival of autumn. Some Greek city-states, including Sparta and Macedonia, even began their calendars with the autumn equinox as the start of the new year.
Across many cultures, the equinox has symbolized balance, renewal, and preparation for the colder months ahead. For farmers, it traditionally marks the season of sowing, while for everyday life it brings cooler evenings, shorter days, and the first signs of nature’s seasonal transformation.
