Um....I have been to Beijing during the summer and July is the hottest month--it gets unbearable hot there and unlike HK it's not like everywhere you go has air con either so it doesn't matter. And the thing that people go to Beijing to do is site-see. There is Tiananmen Square, The Forbidden City, The Summer Palace, The Temple of Heaven as well as the Great Wall. But all of these are outdoor destinations and believe me, it's not much fun to be hanging out, outdoors in Beijing in July. One summer my husband and I went there at the beginning of July and we went to Tiananmen Square--it was so hot that the only people in the square (which is usually PACKED with people) were myself, my husband and a few people selling drinks and icecream under umbrellas--even the guards were chilling in the shade on the side of the street. So, the best time to visit Beijing, I think is in the spring (April-May) or the fall (August-September) because you avoid the heat and the chill.
Have you thought of going to someplace like Yunnan? We used to live there and they have some very beautiful places to go and see as well as the highest concentration of ethnic minorities represented and it never gets too overly crowded there and although it is very far south, because a lot of the places are up in the mountains, the weather is very temperate.
