I've been to Israel for months on end and it is rarely dry, usually quite a bit of humidity. I use the same products I use at home, always wear a sunhat, and if you have a safe style to put your hair up you won't need as much product as you expect. I have been able to wash, condition and air dry my hair twice a week with this plan. The Birthright trips are power packed and you will not have time to primp, so have a simplified grooming plan, a hat, sunglasses, and some scrunchies! and sunscreen! and sunscreen for lips! Have a wonderful time!