I am planning to visit Qinghai in August. What is the average temperature? warm clothing required?

Qinghai covers a large area and the temperature is different for different places.
Generally speaking, for Qinghai, the average temperature during that time is around 10 to 25C. it is suggested to take a thin sweater and a thick coat as well as some T-shirts.
The T-shirts can be worn during the day time and the coat and thin sweaters are needed at night.