Normally, the most comfortable season of the year is Spring and early autumn (September to early October). During these periods, temperatures are comfortable for travel throughout China (about 50-72F) with a limited amount of rain. September for example is the only month in the year when the ancient and valuable paintings of the Beijing Palace Museum are displayed due to proper climate conditions (low humidity and proper temperature). Spring is also a good season for traveling, but it's so short in China. The Spring always passed fast.