A couple of weeks ago when the temperature started dropping and I was out walking the dogs I said in passing conversation to some walkers "Autumn's coming". At the back of my mind there was also the low sun in the sky making driving difficult early that morning and that the nights were starting to draw in.
With the changes in our weather patterns in recent years the start of Autumn seems to move as well in my simple approach. This year for example September and early October still felt like Summer to me!
Then the old scientific upbringing kicked in and I felt the need to get a little more accuracy and find out when it officially begins in the UK.
Like many things in life there is no single answer. In fact there seem to be 3 answers!
How did people manage before Google and Wikipedia?
Seasons are fundamental to how we understand the climate and the environment, but for hundreds of years academics have argued that their specialist field is the one which defines the official start of autumn.
In meteorological terms autumn begins on September 1, as each season is defined as a three-month period.
Astronomers base the date of the seasons upon celestial events, in this case the autumnal equinox, when night and day are of equal length. The equinox occurred on September 23 this year. Astronomical seasons therefore are about three weeks behind the meteorological ones.
One thing both methods have in common is that the dates are fixed by the calendar and don't take into account what is actually happening in nature, which is after all how most of us understand the notion of seasons.
The third definition of the start of autumn, which is more fluid, comes from phenology – the study of periodic plant and animal life cycle events ( a good pub quiz answer!).
The start of autumn in this field is dictated not by a set date or a single event, but the changes in the natural world.
See some local examples we published a couple of days ago
Autumn may be deemed to have arrived at the first tinting of oak or beech trees, the appearance of ripe sloes or elderberries and the arrival of winter migrant birds such as redwings and fieldfares. Winter begins when native deciduous trees are bare, and so on.