Flight prices from the East Coast

We've been bouncing some ideas around about our wedding dates, and have figured out that to fit in with various guests' college/work/family commitments, the ideal dates would be last week of May, first half of June, or any time in August.  What I can't figure out is what the difference in flight prices between these dates would be for our American guests (mostly coming from Boston).  June in the US is summer holidays I think, and then most schools go back mid-August?  But then summer holidays in the UK are end of July to beginning of September.  So do you think June and the end of August is still peak season for flights, or might it be a little bit cheaper?

any time during the summer months = higher prices. Some fares MAY drop on October 1, but summer is a killer as demand > supply.

In the 'olden days' the air miles free flights generally only were available after October 1, which tells you something about the drop off in fare-paying customers.

I think you can count on summer "peak" prices during any point from about May 1st until September 30th. Although from my experience with looking for airfare this year, even the off-season prices were only marginally cheaper than peak season rates.