When is First day of fall?
In 2027, the first day of fall is Thursday, September 23, 2027, at 2:02 AM EDT (U.S. Eastern time).
The astronomical start of autumn in the Northern Hemisphere. Day and night are close to equal, and nights grow longer until December.
How the date is set: The September equinox (September 22 or 23).
The date in other years
A short history
The September equinox (or southward equinox) is the moment when the Sun appears to cross the celestial equator, heading southward. Because of differences between the calendar year and the tropical year, the September equinox may occur from September 21 to 24. At the equinox, the Sun as viewed from the equator rises due east and sets due west. Before the Southward equinox, the Sun rises and sets more northerly, and afterwards, it rises and sets more southerly.
From Wikipedia’s article September equinox, by its contributors, under CC BY-SA 4.0.
Related days
Sources
- U.S. Naval Observatory: Earth’s seasons Dates
- Wikipedia: September equinox Short history (CC BY-SA 4.0)