china visit in september, what about the weather?

How is the weather in mid september in shanghai? Should we bring summer clothes and a light sweater or a light jacket for the evenings? Which place or area is good for shopping in shanghai for souveniers, clothing, handbags,shoes,tailor shops(with materials to buy)? How about Nanjing road? Is there any Indian restaurants in nanjing road in shanghai or wangfujing road in beijing? How is the weather in Xian in mid september and is there any indian restaurant in xian on main street east(city midst dist.)Is there good shopping also in xian? Thanks in advance for your help!