is it a good time to visit JiuZhaiGou on 3rd week to 4th of Oct?

Well, it has the most enchanting landscapes in October there. It is also nice for you to go there on the 3rd to 4th week of Oct. However, during this season, the average temperature varies greatly between 4~13C, so some warm clothing are also necessary at this time. Oh, do not forget to take a raincoat with you since it may often have light rain there.