Riyadh: Tomorrow, Monday, September 22, marks the astronomical arrival of autumn in the Northern Hemisphere, when the sun will be directly overhead at the equator in a phenomenon known as the autumnal equinox. At this time, the length of day and night is nearly equal. Autumn will continue until December 22, coinciding with the winter solstice.
According to Saudi Press Agency, member of the AFAQ Society for Astronomy Barjas Al-Fulaih stated that the arrival of autumn does not mean an immediate drop in temperatures, as the shift in climate occurs gradually in the following weeks, becoming more noticeable with the onset of November.
He noted that this transitional season is significant, as the atmosphere gradually shifts from the intense summer heat toward the cold of winter.
The autumnal equinox is regarded as one of the most notable astronomical phenomena, reflecting the precision of the cosmic system and the regularity of the Earth's orbit around the sun. Historically, it has also marked an important moment in human agricultural and climatic life, as it coincides with the beginning of harvest seasons in many ancient civilizations.