One of the main reasons why cruise fares, air fares, and land tours differ in price from one month or season to the next is because of the weather pattern--temperature and precipitation expectations. Yes, in Cina the weather in October is usually better than the weather in November. If you go to theweatherchannel.com, you can find 10-day forecasts as well as average monthly temperature and precipitation levels for cities all over the world.
I just returned from a Viking River Cruise with Viking. Everyone in my group of 24 experienced world travellers loved it--many calling it their best trip ever. The crew is exceptional and the guides are THE BEST--especially Maggie! Three different guests sent me copies of journals they kept of the trip, and I have their permission to share them with others. One of them is comes with great photos. If you'd like me to forward them to you, please send me your email address.