Autumn equinox to fall on September 23, 2026, says Jeddah Astronomy Society

The Jeddah Astronomy Society has announced that the autumn equinox will occur on September 23, 2026, marking the astronomical start of autumn in the Northern Hemisphere.

The society explained that residents of northern regions observe the seasonal change through natural signs in the night sky, as northern nights gradually lengthen after months of extended daylight.

The society added that the aurora borealis becomes one of the most prominent celestial phenomena during this period, especially in areas within the auroral zone.

Opportunities to witness auroral activity increase around the equinoxes due to the alignment of Earth's magnetic field with the solar wind, creating favorable conditions for magnetic reconnection and the transfer of energy into the magnetosphere and upper atmosphere.

The society noted that this effect is known as the Russell–McPherron effect, where energetic particles linked to solar activity collide with oxygen and nitrogen atoms and molecules in the atmosphere, causing the gases to glow in various colors such as green, yellow, and sometimes red and violet, producing the polar lights in the sky.

Long-term records of geomagnetic activity show a clear trend of increased activity around the equinoxes compared to other times of the year. Therefore, the weeks of September and October are among the best periods for aurora watchers in northern regions, although the appearance and intensity of the aurora depend on actual solar activity and the direction of the solar wind's magnetic field at that time.

As autumn approaches, the night sky offers a variety of scenes, from the changing length of night to the return of optimal opportunities to view the aurora borealis in the far north.