A note before you act: entry and transport policies can change. Recheck the official source relevant to your nationality and route before departure.
Spring and autumn are the broad favorites
April, May, September and October suit many classic routes, but China’s scale means no single month is best everywhere. Regional climate matters more than a national average.
Build around what matters most
For hiking, harvest, festivals or lower prices, a more specific seasonal window may be worth accepting less predictable weather.