I plan to go Jiuzhaigou around early April or early oct 2014. Which month is better? What's d weather ?

Although the beauty you see is different in different time of a year, but I think the best visiting time is the mid October, when all the ponds are full of water. It is wonder.
If you cannot go in the mid October, you can go there in the early October, the scenery is similar.
The average temperature is around 13C during that time and I think the coat and T-shirts are necessary.