I have had the same package of wet wipes for about 2 years now (opened the day I bought it) and it was the same package I took to UT with me last fall. They are still moist. Not as moist as at first but not dry yet...I think a week in the desert is not a problem. I think it would last quite a while since I was living in UT when I bought it and then lived in ID for a while...both hot and dry in the summers.