Going to a wedding in Israel in Nov! What to wear?

So FH lived in Israel for a few years for work and has some good friends living there...(even though he's a nice Catholic boy from Montana)..haha...his best man lives there and we are going to his wedding in Nov...he says Israeli weddings are nothing like NY ones (he's been to a few there), much more relaxed...grooms usually wear a shirt & pants...and brides a nice dress but nothing like ours...FH said women don't usually wear the cocktail style dresses we do...i don't want to be the stupid American friend that shows up looking out of place! haha Anyone ever been to a wedding there? any suggestions?TIA!!