The weather in the UK may still be warm and sunny but the leaves are starting to fall from the trees and the nights are gradually getting shorter, which is a sign that autumn is almost here.
But the exact start date of the autumn season depends on whether you follow the astronomical calendar, or the meteorological one. Astronomical seasons refer to the position of the Earth’s orbit in relation to the sun, taking into account equinoxes and solstices. Since the seasons vary in length, it means the start date of a new season typically falls on a different day each year.
According to the Met Office, astronomical autumn this year starts on Monday, September 22, and will end on Sunday, December 21.
The equinox defines the transition between the seasons of the astronomical calendar and occurs twice a year, with the spring equinox falling in March and the autumn equinox falling in September.
The Met Office explains: “Equinoxes and solstices mark the astronomical transitions between seasons. The Earth’s elliptical orbit means these dates can vary slightly each year.
“The autumn equinox signals the point when the northern hemisphere begins to tilt away from the Sun, leading to shorter days and cooler temperatures. From this point, nights become longer than days until the winter solstice.
“Autumn in the UK is also typically associated with falling temperatures and shorter days. The season often brings unsettled weather, especially later on, when Atlantic depressions can lead to stormy conditions and strong gales. These changes are part of the natural shift as the country prepares for winter.”
But if you follow the meteorological calendar – which is instead based on the annual temperature cycle – then autumn will always start on September 1 and end on November 30 every year.
The meteorological seasons split spring, summer, autumn and winter into four periods of up to three months each and these coincide with the Gregorian calendar, meaning the start date of each new season doesn’t vary year on year.
So with the arrival of autumn almost upon us, it means another clock change is looming. The clocks will go back by one hour at 2am on Sunday, October 26, officially marking the end of British Summer Time and the return to Greenwich Mean Time.
But while it signals that summer is over and the evenings will be darker, there is a positive in that you get to enjoy an extra hour in bed when the clocks change.
While it’s only an hour difference, the changing of the clocks can cause disruption to your body clock and mood, so experts advise adjusting your bedtime by around 15 to 30 minutes each night leading up to the change to get acclimatised.
