it all depends if you can afford living in miami or san diego, they are expensive as far as weather san diego would do it for me, miami is to humid hot and threats of hurricanes are not for me also crime rate in miami is way up there.so way your options and see what is best for you I personally would choose san diego if I could afford it.
IF you can do it... definitely San Diego... Miami is a hell hole with tons of humidity and hurricanes... but it is expensive and it is hard to get a job right now so maybe try and have a job before moving and being disappointed but I definitely say San Diego!