From Chengdu to Dalian-Weihai-Penglai-Qingdao next week. What is the local temperature? What is suitable for wearing? Is it cold to go to Yantai by boat from Dalian at night?

Just wear a long-sleeved coat in the morning and evening. It will be very hot at noon. In fact, long sleeves are unnecessary for the queen mother. Dalian is like this. It will be warmer if you go south to Qingdao, but it will be cold if you wear too much by boat. Anyway, it won't be too thick. The weather suitable for tourism in Dalian will last until November.