The iconic "changing of the leaves" is actually a process of unmasking. As days shorten and sunlight becomes less intense, deciduous trees stop producing chlorophyll—the pigment that keeps leaves green. This allows other pigments, like (yellows and oranges) and anthocyanins (reds and purples), to finally take center stage before the leaves eventually drop. The "Cozy" Aesthetic: A Cultural Phenomenon
This fixed schedule makes it much easier for agencies like the National Weather Service to compare weather statistics from year to year without dealing with shifting equinox dates. Fall in the Southern Hemisphere when is the season of fall
This is the "official" calendar start marked by the Autumnal Equinox . This is the precise moment when the Sun crosses the celestial equator, making day and night nearly equal in length. Northern Hemisphere (2026): September 22 to December 21. Southern Hemisphere (2026): March 20 to June 21. The iconic "changing of the leaves" is actually
While most people look for the first colorful leaves to signal the season, experts use two specific systems to pin down an exact date. The "Cozy" Aesthetic: A Cultural Phenomenon This fixed
Meteorologists and climatologists use a simpler, more practical system. They split the year into four fixed, three-month seasons based on annual temperature cycles and ease of record-keeping. This method allows for consistent month-to-month and year-to-year climate comparisons.
For the general public, fall is defined by environmental cues rather than calendar dates. This is the "Vibe Check" of seasons.
The season of fall typically begins on according to meteorologists or around September 22 according to astronomers in the Northern Hemisphere . These two distinct methods of tracking the year ensure that whether you are planning for the harvest or checking the weather forecast, you have a consistent way to define when the seasons change. Fall 2026 Key Dates