There are festivals in Tivoli, but a lot of them aren't in the summer. For example, there is a street painting festival which seems to go on every year on the first Saturday in October. There's also apparently a Halloween block party, an Easter egg hunt, and a tree-lighting event when Christmas rolls around.
The only thing remotely resembling a festival that takes place in the summer is the "Yard Sale Day" they have, where Tivoli becomes somewhat of an outdoor marketplace, at least where there are people participating.
