Well this could be the dumbest question ever... but coming from a city where late fall/winter months mean cold-weather clothing (sweaters, boots, no sandals) -- I was just wondering (due to an upcoming trip) in San Diego whether the calendar months help to dictate clothing and shoe style/color or if it's summer year 'round

Bring sandals, and summer styled clothes (light/bright colors).... or something for warmer weather but less summer-like?
Thanks in advance!