Jiuzhaigou Valley in July

October hits the sweet spot – autumn colors peak, crowds thin slightly after National Day holiday, and weather stays mild. The maples and birches turn the valleys into a kaleidoscope that rivals the lakes themselves. Spring (April-May) brings fewer crowds and blooming rhododendrons, but some higher elevation areas might still have snow. Summer means peak crowds and afternoon thunderstorms, though the waterfalls run strongest then. Avoid Chinese holidays like the plague – Golden Week in October and Spring Festival create human traffic jams that make the park miserable. Weekdays always beat weekends, and early morning entry (8am) gives you the best light and smallest crowds before the tour buses arrive.