The September equinox occurs at 00:05 UTC on Wednesday, September 23, 2026. Because that moment is just after midnight in Coordinated Universal Time, many people in the Americas will mark the event on Tuesday, September 22.
It begins astronomical autumn in the Northern Hemisphere and astronomical spring in the Southern Hemisphere. The event is global and instantaneous, even though local calendar dates differ.
September equinox 2026 in major time zones
Converted from 00:05 UTC on September 23, the equinox occurs at approximately:
- 8:05 p.m. EDT on September 22 in New York and Toronto
- 5:05 p.m. PDT on September 22 in Los Angeles and Vancouver
- 1:05 a.m. BST on September 23 in London
- 2:05 a.m. CEST on September 23 in Paris, Berlin and Madrid
- 5:35 a.m. IST on September 23 in India
- 10:05 a.m. AEST on September 23 in Sydney
Daylight-saving rules can vary by location, so readers should confirm the offset used in their city.
What physically happens at the equinox?
Earth's axis is tilted by about 23.4 degrees relative to its orbit around the Sun. That tilt creates the seasons. At the September equinox, the Sun's apparent path crosses the celestial equator moving southward.
The subsolar point—the place where the Sun is directly overhead at local noon—crosses the equator. Afterward, the Northern Hemisphere receives progressively less direct sunlight until the December solstice, while the Southern Hemisphere receives more.
Is day exactly equal to night?
Not quite. “Equinox” is often simplified as equal day and night, but most locations experience slightly more than 12 hours of daylight on the date.
There are two main reasons. Sunrise and sunset are measured using the upper edge of the Sun rather than its centre, and Earth's atmosphere bends sunlight so the Sun appears above the horizon when it is geometrically below it.
The date on which day and night come closest to 12 hours each is sometimes called the equilux. Its timing depends on latitude.
Why seasons do not begin on the same date every year
A calendar year is not an exact number of Earth orbits. Leap years and the difference between civil time and orbital motion cause equinox times to shift. That is why the September event can fall on September 22 or 23 rather than a permanently fixed date.
How to observe it safely
No special visual event suddenly appears in the sky at 00:05 UTC. The change is an astronomical crossing, not an eclipse. Never look directly at the Sun without certified solar-viewing protection.
You can still observe the seasonal effect by recording sunrise and sunset positions over several weeks. Shadows at solar noon also change as the Sun's declination moves south.
The exact time is listed by Timeanddate's September equinox guide. For another major sky event, read our 2026 total solar eclipse guide or explore more news explainers.
