The autumn season will arrive in Azerbaijan on September 23 at 04:05:08 Baku time.
According to the information provided to “Elchi” by the Department of Astrophysics of the Faculty of Physics at Baku State University, this moment is called the “autumnal equinox.”
At this time, day and night are almost equal, and the Sun rises exactly in the east and sets in the west. However, due to atmospheric refraction and the angular size of the solar disk, the length of the day is not exactly 12 hours and is slightly longer than the night. During its annual movement, the Sun crosses the celestial equator, moving from the Northern Hemisphere to the Southern Hemisphere. From that moment on, autumn begins in the Northern Hemisphere and spring begins in the Southern Hemisphere. After this, days in the Northern Hemisphere gradually shorten, and nights begin to lengthen.
The change of seasons is not related to the change in the Earth’s distance from the Sun, but to the Earth’s movement around the Sun and the tilt of its rotation axis at approximately 66.56° to the orbital plane. It is precisely because of this inclination that the angle at which solar rays hit the Earth’s surface changes throughout the year, creating the seasons.
In 2026, the astronomical autumn will last 89 days, 21 hours, 45 minutes, and 1 second, and will end with the winter solstice occurring on December 22.
From that moment on, astronomical winter will begin in the Northern Hemisphere, and astronomical summer will begin in the Southern Hemisphere.