The fall equinox (also called the autumnal equinox) marks the astronomical start of autumn in the Northern Hemisphere. This countdown tool below tracks the days, hours, minutes, and seconds until the next equinox.
When is the fall equinox?
The fall equinox typically falls on September 22nd or 23rd, depending on the year and your timezone. At the equinox, day and night are approximately equal length everywhere on Earth.
Countdown features
- Live countdown – Days, hours, minutes, and seconds until the equinox
- Visual progress bar – See how far through the wait you are
- Automatic year rollover – After each equinox passes, the tool targets the next one
- Timezone detection – Attempts to show the countdown in your local time
The astronomy of the fall equinox
At the fall equinox, the Sun crosses the celestial equator heading southward – the opposite of the spring equinox. After this date, nights grow longer than days in the Northern Hemisphere until the winter solstice.
Check out my sun angle calculator to see how the sun's position changes throughout the year.
