For France, August! Because most of that month is when all the French are out on vacation. The only thing is, most of the best baeikres are closed b/c they are out on vacation. When I visit my sister i try not to go in August just so I can have the best bread and pain au chocolat mmmm. But I would think that Nov would be pretty dead. Its kind of cold, school is back in session. I know when I was in london, barely anyone was in the hostels in Nov. It was dead! Same with Germany and Belgium. So I think Nov, Feb, March, April I would think since school is in session. But avoid Spring Break and Winter break, kids go with the schools on vacation and they mostly will stay in hostels. Bah, made that mistake in Austria!!!I found Nov and Dec time to be pretty dead and even towards the end of Oct.