September marks the beginning of autumn weather. The summer heat begins to wane, and the weather in the north becomes cooler. In South China, the hot and humid weather continues but it is gradually replaced by autumn cooler and drier weather by the end of this month. There may still be a week when there is prolonged rain, but it is usually not as heavy.
China Highlights lists five best places to visit in the cool September.
Clothing: Shorts and short sleeves are enough during the daytime on most days, but bring something warmer for the evenings.
Other recommended items: umbrella, sun cream, sun glasses and sun hat.
September is still a good time to visit Tibet, with still enough warmth for comfort, and the visibility is good. See Tibet Weather
The weather conditions are pleasant. The suitable time to travel along the Silk Road is from late spring to early Autumn (May, June, July, August, September and October, to be specific). Although summer weather can be scorching, it is a dry heat, so more comfortable than in the tropics and coastal areas. The scenery is the best when the fruit becomes ripe, with flowers in full bloom and green grass in the grassland areas. See Silk Road Travel Tips
September's weather still permits a pleasant visit to the glasslands. See Inner Mongolia Weather