When is the first day of fall 2023?

NEW YORK (PIX11) -- With August winding down, memes of pumpkin spice lattes, football and "Spooky SZN" are getting pushed into our social media algorithms. But one question remains: When is it officially fall?

In the United States, the 2023 fall season officially starts on Sept. 23, according to the Farmer's Almanac.

While the first day of a season may feel like it was chosen by throwing a dart at a calendar, the actual reasoning is based on science — specifically, the positioning of the Earth and the sun. This is where the term equinox comes into play. Equinox is based on the Latin words aequus, which means equal, and nox, which means night.

What occurs during an equinox?

On the equinox, the length of day and night are about equal.

When an equinox happens, the sun crosses the equator from one side to the other. Many people north of the equator will experience fall-like weather during the autumnal equinox, while those south of the line will experience spring because the sun’s rays cross from the Northern Hemisphere to the Southern Hemisphere. The opposite happens on the vernal equinox, or the first day of spring.

So for one day, when the sun is right over the equator, both hemispheres enjoy roughly the same amount of daylight.

When do we 'fall back?'

There’s one more thing to remember: Just because it’s the first day of fall, it doesn’t mean our clocks are "falling back" by an hour. That won’t happen until the end of daylight saving time on the first Sunday of November, which falls on Nov. 5 this year.