Festival weather - come rain or shine?

This seems to be what everyone going to a festival, or other outdoor event this summer, wants to know right now. I'm no weather expert but I certainly know what a difference it makes!
For UK event forecasts here is a general link. If the one you are planning to visit is not listed then either type in the nearest town to it here, or ask for it to be added to the list.
The one most sought now is Glastonbury 2008.

The one I'm more interested in is Latitude 2008 as that is where I'm headed in mid-July!

Let's all hope for the best, wherever we are going!