When to visit?

Venice Biennale is held from June to November. (Please click the link for the 2011 opening schedule) When should we visit?
In accordance with the opening of Biennale, there held some collateral exhibitions in Venice. If you don't want to miss them, you should go as early as possible. Some of them may be opened only during summer.
However, there are so many visitors from June to August that people may have line up  in front of exhibition rooms. If you want to save time and see comfortably, early autumn is the best season. In September, it is cool enough to walk around very comfortably. The later you go, the better you can avoid the crowed.
The travel expense including flight and hotel is the highest in summer, July and August. If you want to save money, you should go later. The later, the cheaper. In October and November, it is terribly cold and Aqua Alta, exceptional tide peaks, could occur.     Be careful and ready for the flood.