So supporting evidence is needed, and I present that as follows;
The mushroomers are out in force. Russians go crazy for mushrooms, it seems, and on any trip out of the city at this time of year you will pass a number of home-made stalls on the edge of the road with (usually) babushka's perching on upturned plastic crates, behind a plastic sheet on the ground covered with interesting looking fungi. I'm not a great mushroom lover myself (can't really be doing with the texture, I'm afraid), but Muscovites will happily load their car up with their family, some charcoal, some shashlik and some beer and trek out to the forest to make a day of their foraging expedition for nature's bounty. I'ld quite like to try it, actually - the trip out, that is - just as long as I don't have to eat the results.
The supermarkets are full of empty jars and lids. This is not only for the home-prepared stewed fruit, jams and vegetables from the garden at the family dacha which are brought back into the city in triumph, crammed into the back of the car, as the weather turns colder. The jars are also used to store the mushrooms mentioned above, which are often preserved salted. Note: if you are not keen on mushroom's texture in the first place it ranks somewhere in the 7th circle of culinary hell when you are presented proudly with a dish of salted mushrooms prepared to an old family recipe by your host, and which you really feel you must try or cause offence.
*shudders theatrically*
The traffic gets significantly worse. This morning it was an 8-lane day as I joined the highway. 8 lanes where 3 are marked, that is. Gosh, I just can't wait for the first snow in a few weeks time when no-one has their winter tyres on yet and things get even jollier...
The new parents at the school start to lose the 'rabbit in the headlights' look that they had in the first few weeks of term when they would arrive to drop their children off, having battled the traffic all the way across town** and made the mistake of thinking that they were driving in an environment where 'normal' traffic rules apply. They don't. Luckily it only takes 4 weeks to get used to that, and in any case most of these expats rarely sit behind the wheel of a car, letting their driver take the strain...
And finally, I know it is Autumn because I have already seen Russian children dressed up in snowpants and hats. In September. At 15 degC. I mean, I know it pays to be prepared, but...
** This is invariably the result of allowing their working partner / working partner's HR department to choose their accommodation on an earlier - solo - visit to Moscow, when proximity to the office was ranked more highly than proximity to the children's school. Which is all very well until you realise that whilst one member of the family only has a ten minute commute, everyone else is sitting in the car for around 3 hours a day...