Since the Peruvian climate varies dramatically depending upon elevation and season, it is difficult to offer many generalizations. Comfort is the rule and fancy clothes are not necessary. Peruvians are used to seeing travelers so shorts, sandals, and jeans are perfectly acceptable. Not bulky layers are key as the temperature shifts radically, and it gets VERY COLD the minute the sun goes down or clouds roll in. Just about anything you forget is now available in Peru, so no worries!