Want to avoid peak season of Jiuzhaigou and are there dates where the park is closed?

Usually, the park is open for the whole year round, but it sometimes will be closed due to the terrible weather. If there is heavy snow or mountain slide, the road leading to the scenic area will be blocked. Sep. and Oct. are the best time to visit the place, so in early Oct, it will be peak season. If you want to avoid the crowds, you are suggested to go there in late Oct. or early Nov.