Autumn Equinox 2026: 23 Sept

The season behind the name

Autumn Equinox marks another balance around equal day and night, midway through the traditional autumn season.

These names grew from seasonal observation and farming practice. They describe a traditional seasonal sequence, not a weather forecast for every region.

Autumn Equinox begins at the instant the Sun reaches 180 degrees of apparent ecliptic longitude. It is one of 24 equal 15-degree divisions of the solar year, so its Gregorian position changes only slightly from year to year.

As a qi term, Autumn Equinox marks the alternating mid-month point in the solar-term sequence. It does not open a solar branch month, and it does not open a lunar month.

The time is shown in China Standard Time (UTC+8). A reader west or east of that zone may see the same instant fall on a different local civil date.