September 22 – Fall Equinox: The Transition to Autumn
The Fall Equinox, arriving on September 22nd this year, marks the official shift from summer to autumn. Also known as the Autumnal Equinox, this astronomical event signals the end of long, sun-filled days and the beginning of fall’s cozy, crisp atmosphere.
The term “equinox” derives from the Latin words aequus (equal) and nox (night). On the day of the Fall Equinox, daylight and darkness are nearly equal, each lasting about 12 hours. Afterward, days gradually shorten and nights grow longer, ushering in the approach of winter.
What Causes the Fall Equinox?
The Fall Equinox occurs when Earth’s axis is tilted neither away from nor toward the Sun, placing the Sun directly above the Equator. This unique alignment ensures that nearly every place on Earth experiences almost equal hours of daylight and darkness.
There are two equinoxes each year: one in the fall and one in the spring. The tilt of Earth’s axis, combined with its orbit around the Sun, creates the changing seasons and the varying lengths of daylight throughout the year.
The Changing Colors of Fall
One of autumn’s most iconic features is the dramatic transformation of foliage. As days shorten and temperatures drop after the equinox, chlorophyll—the pigment that makes leaves green—begins to break down. This allows other pigments, such as carotenoids and anthocyanins, to emerge:
- Carotenoids create yellow and orange hues.
- Anthocyanins produce red and purple shades.
This natural process results in the breathtaking tapestry of reds, oranges, yellows, and browns that define the season. The changing colors also signal trees to prepare for winter by shedding their leaves.
Traditions and Celebrations
For thousands of years, cultures around the world have celebrated the Fall Equinox. Many view this time as an opportunity to honor the Earth’s abundance and give thanks for the harvest.
One of the most recognized traditions is the Harvest Festival, which takes place around the equ
