I love little linguistic nuggets like backend.
From
t’Northern Echo(2002):
It is inevitable, in England, that we discuss the weather as it affects each of the seasons - and our weather probably has more bearing on our perception of the seasons than any officially determined date - although there is an old Yorkshire Dales saying that the year consists of nine months of winter and three months of backend.
The term backend, of course, is one which refers to the autumn and although it does not appear in all the conventional English dictionaries, it does feature in one of my specialist dictionaries of the North Riding dialect.
It seems it has its origins in the Danish bagende which refers to the latter end of any period. People do refer to the backend of the week, for example. On that basis, I suppose we could refer equally to a winter backend, spring backend, summer backend and autumn backend but in this part of the world we tend to associate the word with the latter part of the entire year.
Certainly in this region, any reference to "t'backend" means autumn - perhaps not the official autumn, but that part of the year before Christmas such as October and November when the nights draw in, the weather becomes cooler and the leaves begin to fall.
It's fair to say that most of us instinctively know when the weather turns "backendish" even if we are not quite sure how, or if, it is associated with any of the equinoctial periods.