I only went to China’s pavilion (I was only in the expo for one day, and one day is not enough) and I thought it wasn’t as impressive as most people said it was. From what I heard, the best pavilions were UK, France, Germany, Japan, Saudi Arabia, Poland, Israel, Italy, and most (if not all) the Scandinavian countries. However, they take a really long time just to wait on line for them. The American pavilion is a joke. I honestly have no idea why people would want to go there. As for the weather, it was humid and hot when I was there (it was in the beginning of July), so I think the weather should be less overbearing, but I’d still check this out