September Equinox 2026

What this countdown tracks

The clock counts down to the September (autumnal) equinox of 2026, which occurs at 00:06 UTC on Wednesday, September 23, 2026. At that instant the Sun crosses the celestial equator moving southward, astronomical autumn begins in the Northern Hemisphere, and astronomical spring begins in the Southern Hemisphere.

About this celestial event

The September equinox is the second of the two annual equinoxes — the moment Earth reaches the point in its orbit where the Sun appears directly above the equator on the way south. The 2026 instant of 00:06 UTC on September 23 translates to 20:06 on September 22 in New York (EDT), 01:06 on September 23 in London (BST), 03:06 in Moscow, 05:36 in New Delhi, and 09:06 in Tokyo. North America observes this equinox on September 22 local time; most of Eurasia observes it on September 23.

At the equinox, day and night are very nearly equal across the globe; the terminator runs from pole to pole; and the Sun rises due east and sets due west everywhere except the poles. The equinox is the moment when the Northern Hemisphere's daylight begins to fall faster than at any other time of the year — roughly three minutes per day at 40°N — and the Southern Hemisphere starts gaining daylight at the same rate.

The September equinox is the anchor for several cultural calendars. The Chinese Mid-Autumn Festival falls on the full moon nearest the equinox; the Jewish High Holy Days (Rosh Hashanah, Yom Kippur) fall around the same window; and the Hindu Sharad Navratri begins shortly after.

What to expect

The equinox itself is a calendar moment, not a visible spectacle, but the days surrounding it are when the Sun's path across the sky changes most rapidly. At Chichén Itzá in Mexico, the September equinox produces the same serpent-shaped shadow on El Castillo as the March equinox, and the site is open for visitors. Many sites with archaeological alignments — Newgrange in Ireland, the Ggantija temples on Gozo, ancient Mesoamerican observatories — are open for equinox-day visits.

In the Northern Hemisphere the equinox marks the practical start of autumn: the daily decline in daylight accelerates, average temperatures begin their drop, and the autumn star patterns (Pegasus, Andromeda, the rising Orion in the small hours) take over the night sky. The September equinox is also a strong period for aurora borealis activity at high latitudes thanks to the Russell–McPherron effect.

Past equinoxes

• September 22, 2025 — equinox at 18:19 UTC
• September 23, 2024 — equinox at 12:43 UTC
• September 23, 2023 — equinox at 06:50 UTC
• September 23, 2022 — equinox at 01:03 UTC
• September 22, 2021 — equinox at 19:21 UTC
• September 22, 2020 — equinox at 13:30 UTC

How to observe

The US Naval Observatory, UK Met Office and timeanddate.com publish exact equinox times. Stellarium and SkySafari let you visualise the Sun's path on the celestial sphere. Aurora forecasts (NOAA SWPC, AuroraWatch UK) typically show heightened activity around the equinox window — worth tracking if you are at high latitude.

Related countdowns

The September equinox sits between June solstice 2026 and December solstice 2026. Pair with the Saturn opposition 2026, Sukkot 2026 and Orionid meteor shower 2026 on the autumn sky calendar.

FAQ

When is the September equinox 2026? Wednesday, September 23, 2026 at 00:06 UTC. What's the local date in North America? Most of North America observes the equinox on the evening of September 22 local time. Is the equinox the same day everywhere? Within a few hours, yes — but the local clock date depends on your time zone. Why does aurora activity peak around the equinoxes? The Russell–McPherron effect: Earth's magnetic field is best aligned with the solar wind near the equinoxes, increasing geomagnetic disturbance.