First Day of Autumn 2024: Here's when autumn starts - and finishes

It won't be long until the trees are shedding their leaves. | Canva/Getty Images

It may seem like summer has barely arrived, but once again the days are shortening and autumn is on its way.

While the weather may be getting cooler, it’s still a lovely time to be in Scotland, with the leaves on the trees turning golden and the chill of winter still a long way off.

But when does autumn actually start? Here’s what you need to know.

When is astronomical autumn?

When it comes to astronomical autumn we are talking about the a period defined by the Earth's axis and orbit around the Sun. The seasons occur due to the 23.5 degrees of tilt the Earth's rotational axis has in relation to its orbit around the Sun.

Summer ends - and autumn starts - on the autumnal equinox, when the Sun crosses the celestial equator going south. The date of the equinox is not fixed, due to the Earth's elliptical orbit of the Sun.

This year astronomical autumn begins on Sunday, September 22 - a day earlier than last year when it was on Saturday, September 22.

Astronomical autumn ends on the winter solstice, the shortest day of the year in the Northern Hemisphere when the Sun is directly over the Tropic of Capricorn. Again this is not a fixed date and varies from year to year.

In 2024 the winter solstice, and the end of autumn, is on Saturday, December 21.

When is meteorological autumn?

More straightforward is meteorological autumn which always starts on September 1 and ends on November 30.

The meteorological seasons simply consist of splitting the year into four equal seasons of three months each - making it easy to observing and forecast weather consitions in a consistent way.

Using this system spring is March, April and May; summer is June, July and August; autumn is September, October and November; and winter is December, January and February.