Throughout July and August, a number of airlines are offering discount flights to Barcelona from New York, including Delta, Iberia, and Air France. I found a number of different cheap flights to Barcelona for $537 leaving in mid to late July at 7 day intervals.
Cheap Flights from New York City to Europe
Must book your flight two weeks in advance. Dates of travel seem to be fairly flexible, but the cheapest dates are Tuesdays and Thursdays.
This is an ongoing fare special, so no rush to book, and there seems to be quite a bit of flexibility in terms of when you can book.
Frankfurt has one of the biggest and most trafficked airports in Europe, so its no surprise that there are a number of cheap direct flights between NYC and Frankfurt.
Kuwait Airways is offering roundtrip non-stop flights to London for $360