Today, September 22, 2026, marks the autumnal equinox, the astronomical start of fall in the Northern Hemisphere. On this day, the sun crosses the celestial equator, resulting in roughly equal day and night lengths across the globe.
The equinox occurs at a specific moment, not necessarily at the start of the day. In 2026, the autumnal equinox happens at 14:05 UTC (Coordinated Universal Time), which is 10:05 a.m. EDT. This timing means that for many locations, the official start of fall comes later in the day, even though the date itself is September 22.
Meteorologists often define fall as beginning on September 1, based on temperature cycles, while astronomers use the equinox to mark the season. This difference explains why some people consider fall to have already started weeks ago.
The equinox also brings shorter days and cooler temperatures as the Northern Hemisphere tilts away from the sun. In the Southern Hemisphere, it marks the start of spring.
