For many Americans, the fall season begins the week after Labor Day. Kids head back to school, Friday night football kicks off, and Halloween candy, decorations and costumes grace store aisles everywhere. The weather may still be hot and humid here in Hampton Roads, but everyone begins bracing for lower temperatures, shorter days, and longer nights.

Of course, the week after Labor Day is the unofficial beginning of fall. The official first day of fall is...when exactly? The date moves around from year to year, with many of us asking, sometime later in September, "Was today the first day of fall, or was it yesterday? Or is it tomorrow?" Sometime in late March, we usually face the same confusion regarding the first day of spring.

So when is the official first day of fall in 2023? And why is the date different every year? To answer those questions, we have to consult the heavens-in particular, the sun and the Earth's yearly journey around it.
 

The name for the first day of fall is the Fall Equinox. The word "equinox" comes from two Latin terms: aequus, which means equal, and nox, which means night. So equinox literally means "equal night."

According to the National Weather Service, an equinox occurs two times each year when the number of daylight hours and nighttime hours in a single day is equal. This happens because the Earth's axis is tilted neither toward nor away from the sun. Because the sun is over the equator on those two days,  the amount of daylight and darkness is the same across the entire Earth.
The Spring Equinox usually takes place between March 20th and 21st. The Fall Equinox usually takes place between September 22nd  and 23rd.

This year (2023), fall begins officially on Saturday, September 23rd. If one wants to get even more precise, in our region of the eastern seaboard, fall begins that evening at 2:50 am.