Autumn Equinox Marks First Day Of Fall 2024

 Autumnal Equinox as seen from space. Credit: NASA

The 2024 Autumn Equinox falls on Sunday, September 22, 2024. The Autumnal Equinox, as pictured in this NASA Earth Observatory photo, is caused by the tilt of the earth’s rotating axis.

According to the U.S. Naval Observatory, the Autumn Equinox, marking the changing of the seasons from the last day of Summer to the First Day of Fall, occurs on Sunday, September 22, 2024, at 07:44 a.m. Eastern Daylight Time.

"Equinox" means "equal night" in Latin, capturing the idea that daytime and nighttime are roughly equal in length everywhere on the planet.

This applies to the Sun's presence above the horizon but does not account for twilight, which occurs when the Sun’s rays extend beyond the horizon and illuminate our atmosphere.

During the equinox, day and night are of nearly equal length in both the northern and southern hemispheres. The apparent change in the Sun and Moon's positions marks important seasonal transitions, affecting activities like hunting, fishing, and farming.

However, it is not the Sun moving north or south through the seasons. Instead, the shifting angles between the Earth and the Sun, caused by the Earth's axial tilt, create these changes.

The Earth’s axis is tilted 23.5 degrees relative to the Sun and the ecliptic plane. During the December solstice, the axis tilts away from the Sun, while during the June solstice, it tilts toward the Sun, resulting in more or less light in each hemisphere.

At the equinoxes, the tilt is perpendicular to the Sun, distributing light evenly across the planet.

2024 Autumn Equinox and 2024 Daylight Savings Time

Naturally, many people think that with the changing of the seasons comes the changing of their clocks at the beginning of Fall 2024. But this is not the case.

It is true that a helpful way to remember whether to adjust our clocks is "Fall Back" in autumn and "Spring Ahead" in spring.

However, the start of Fall 2024 does not coincide with the end of Daylight Saving Time.

Daylight Saving Time ends after the Autumn Equinox, as days continue to shorten toward the Winter Solstice.

If you are wondering, "When does Daylight Saving Time end?" or "Do we change clocks when Fall starts?" the answer is no. Daylight Saving Time (DST) ends in Florida on Sunday, November 3, 2024.