is june good monthto visit beijing and greatwall of china

I think so, since it is not so hot or damp as in July and August with an average temperature of 24C.

Hi,here!

In fact , it is a good time for visit Beijing in April,May,September and October. It is not cold and not hot.
June is begin to hot, but it is better than July and August.

How many times have you been to Beijing?

If you are first time come here,you should visit the scenic spots of Beijing as follows:
1.The Tian'an men square
2.The forbidden city
3.The Temple of Heaven
4.The Ming Tombs--often for Dingling
5.The Summer palace
6.The Great Wall
7.Visit Beijing Hutong by tricycle.
If you are interest in Cultural art of China,you also could watch Peking Opera and The performs of Chinese Kufu and so on.