Seasons change (as they are wont to do!) and, although apparently some people use the temperature to gauge when the weather gets more chill (freaks, seriously), I think most people have their own personal markers that tell them when winter's coming.
For some, it's a burning desire to cook soup and slow-cooked dishes that take hours to simmer but taste divine. For me, my warm and thick dressing-gown gets pulled off the back of the bedroom door. It gets harder to step out of the nice steamy warm shower into the chilly morning air and there is not a carb on the planet that my mind does not want to put directly in my mouth (seriously - it's insane. I've eaten more white flour - cooked into things, of course - in the last two weeks than I have this entire year).
But the final, unavoidable sign that I need to put my sundresses in the summer clothes box and pull out my winter warmers is when Lucy spends all day following me to wherever I am working and uses whatever body part she can get closest to for extra warmth.
Goodbye, summer. I'll miss you while you're gone! Don't stay away too long.