Philadelphia is a fairly casual city, although men will need a jacket and tie in some of the better restaurants. Jeans and sneakers or other casual clothing is fine for sightseeing. You'll need a heavy coat and boots for winter, which can be cold and snowy. Summers are hot and humid, but woman may wish to bring a shawl or light jacket for air-conditioned restaurants. Many areas are best explored on foot, so bring good walking shoes.