# Autumn 2027

- Date: September 23, 2027, 12:00 AM (UTC) — 2027-09-23T00:00:00.000Z
- Category: Holidays
- Page: https://www.watchisup.com/holidays/autumn

Live countdown to autumn 2027, computed from the real equinox rather than a fixed date. Personalise it and share it on WhatsApp.

Autumn 2027 begins at the **September equinox**, usually on 22 or 23 September. The countdown above targets the exact astronomical instant, when the Sun crosses the celestial equator on its way south.

**Daylight disappears fastest right now.** Contrary to a common impression, light is not lost most quickly in December but around the equinoxes: at mid-latitudes we lose close to four minutes of daylight every day at this point. At the solstices the daily change is almost nil.

**Why leaves change colour.** The tree stops producing chlorophyll, the green pigment that masked everything else. The yellow and orange carotenoids were already in the leaf all year: they simply appear once the green withdraws. The reds are different — anthocyanins, manufactured late, at the very moment the leaf is emptying its reserves.

**The clocks go back** shortly afterwards: the last Sunday of October in Europe, the first Sunday of November in the United States and Canada. The two continents therefore spend a week out of their usual time difference.

**Two autumns coexist:** meteorologists start theirs on **1 September**. This countdown tracks the astronomical one.

Full screen, this countdown follows the equinox second by second. **Photo & camera mode** lays it over turning leaves or a rain-streaked window and hands you the image, built in the browser with nothing uploaded. For a school term or a year-end deadline, create your own timer.