When exactly is the autumn equinox 2025? Exact date, time, and what it is explained
Depending on who you are speaking to autumn has already arrived or is just about to.
The leaves have started off the trees, we’re considering popping the central heating is on, and the nights are drawing in - three of the signs that autumn is upon us.
In fact, even though it has been feeling autumnal for a few weeks now, the season only starts this week, astrononically speaking.
That’s because we are about to experience the autumn equinox. Here’s everything you need to know about it.
What is the autumn equinox?
The reason that we have seasons on Earth is because out planet’s axis is tilted at 23.5 degrees as it orbits the sun. That is why the seasons are different in the northern and southern hemispheres, depending on which part is closest to the sun as we spin through space.
An equinox happens when the tilt of the Earth’s axis is at a right angle to the sun, meaning that there are nearly aqual amounts of day or night all over the world as the sun is directly over the equator.
This happens twice a year - at the start of spring and at the start of autumn.
When is the autumn equinox?
The autumn equinox this year will take place at exactly 7.19pm on Monday, September 22.
The date of solstices are not fixed, due to the Earth's elliptical orbit of the Sun. Having said that, the autumn equinox always falls at some point between September 22-24.
Why do some people say that autumn has already begun?
The autumn equinox marks the start of autumn astronomically, but meteorologists mark the start of autumn on the first day of September, dividing the year into four three-month seasons. So winter follows in December, January and February, spring in March, April and May, and summer in June, July and August.
It was dreamed up by scientist according to "sensible weather patterns" in order to keep records - in other words winter falls when temperatures tend to be at their lowest.
When does winter start and when is the shortest day of the year?
Again, winter can be said to start at two different times, depending on the system you are using.
As we’ve covered, meteorologically it starts on the first day of December, but astronomically is starts on the winter solstice. This is when the North Pole reaches its maximum tilt away from the warmth of the sun. The winter solstice is also the shortest day of the year.
This year, the winter solstice occurs at 3.03pm on Sunday, December 21.
When do the clocks go back?
We still have a bit of time to go until we gain an ‘extra’ hour of time. The clocks go back this year on Sunday, October 26.
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