Winter season is at it's start. For me the most obvious sign is - besides freezing temperatures - the Christmas markets. They take place from the week of the first Advent until the day before Christmas Eve. The markets are set up in the city centre and usually consists of little stalls selling all kinds of crafts, Christmas items and winter items (e.g. hats, scarfs, clothes). The majority of the stalls though are offering food and beverages. Very popular is mulled wine. The stalls selling this are the most crowded. Personally I prefer hot chocolate or hot apple juice :-)
Below is a picture of such a stall (mulled wine, bratwurst etc.). The stall is quite large and hosts a gigantic version of a traditional Christmas candle pyramid: This pyramids are originally from the Ore Mountains of Germany and are thought to be the predecessor of the Christmas tree. The pyramid consists of several platforms with a long pole in the middle. At the upper end of the pole there is propeller driven by candles. The heated air spins the propeller and the discs connected to the pole. The big pyramid version is just for decoration though and makes an excellent meeting point.

I love the Christmas markets! In particular since it's getting dark so early the markets are creating a cozy atmosphere with all the lights and decorations and smell of food. But also during day time it's a hustle and bustle. The picture below was taken on a weekday at lunch time!