The Christmas decorations in London typically go up in mid-November. You can expect to see Christmas trees, lights, and other festive decorations in the city's streets and shops. The decorations are a major part of the Christmas spirit in London, and they can be seen all over the city, from the West End to the East End, and from Covent Garden to Piccadilly Circus. The decorations add a festive atmosphere to the city and bring people together in the spirit of the holiday season.