We're going to Qingdao from March 10 - 28. Should we bring heavier jackets? Should we expect rain?

Hi, Lu.
Currently, it is hard to tell you the exact temperature and climate, since it is so early.
According to the previous records, the general situation can be told. The average temperature is around 3 to 10C and do not rain a lot.
So I think the heavy coat is necessary, but the jacket is not necessary. For the rain, it seldom happens.