Hi Laura,
It's hard to remember unless I take out my notes and medical records. I think the majority of them were in June, if I average the attacks that month would have the most votes. I have had November, December, January and February ones too. In my part of the lower 48, it in Summer in June and Winter in December, if that helps.
I think seasonal for me. Twice a year, or occasionally only one. Last was June 15,2008 and I lost the whole summer again. I hope now that I am on LDN the relapses will be once or never a year..

Thanks for asking. It's an interesting survey.