The best time of Jiuzhaigou is every Sep and Oct when the natural scenery is in the most beautiful season. If you worry about the crowded peope and the cold weather, please come to Jiuzhaigou in the middle of Sep.

Yes, as I know, the Sichuan Airlines has opened airlines between Jiuzhaigou and Shanghai Hongqiao Airport&Hangzhou already.

Oh, you mean it's already snowing now in Oct? I think I had heard a China lady from a tour agency telling me that 3 weeks ago.

hmm...wonder if the leaves would still be on the tree in early nov?

No it's not that cold in Jiuzhaigou at the moment. I find accuweather.com gives quite a good forecast. There has been quite a lot of rain but also a few sunny blue sky days.

Sichuan airlines are running flights from Beijing as well. I looked for schedules on ctrip but couldn't find any. Maybe on the sichuan airlines site?

To avoid the crowds a good time to come is just before or after the national holiday in May or October. That is when most Chinese people travel. If you get to China the week after those holidays there are usually less people and it's also the prettiest seasons.

April is also beautiful. There is still snow on the mountains and the summer greens are starting to come out.