Usually you will be travelling with other Monkey Business passengers, which means that you have a ready-made group of new people to talk to. Most of the other passengers, however, are still ordinary Chinese, Mongolian and Russian people, so you have plenty of opportunity to mix with other cultures and share a drop or two of vodka if you want. By all means take a good book, but you'll be surprised at how easily the time passes just watching the countryside slide past. A good question. May. This is when the local people issue a long sigh of relief that the winter is over and the countryside starts to come alive.
Summer is the peak season and the weather is warm and with a good deal of sunshine.
There are never really hordes of tourists but insects can be a problem. The days are long and the locals make the most of this with life being very much outdoor orientated. Book well in advance for tickets at this time. Autumn is a beautiful time, especially if you can catch all the colours around the end of September. The weather is great during the day but at night the first signs of winter can be felt as the thermometer plunges.