Unexpected surprise

Over the past few days (up until today, that is), the weather here in Tver has absolutely wonderful-highs in the 70's and sunny. In fact, it has been quite unexpected. From these past few days, I noticed that everyone was wearing pants (no surprise) but also their jackets. I asked a few of the teachers here why everyone wears the extra layers of clothes, even when not necessary. I was told this: "It is autumn, and we need to dress like it is autumn--even when it is not like autumn." They told me that it would be out of the question to wear anything resembling summer, like shorts, even if the weather is appropriate for it.