We will be in San Diego the week after Christmas. I want to visit Pacific Beach and Mission Beach areas. Will there be lots of people at the beach that time of year? I know the water will be VERY cold, so we don't plan to try swimming or anything. I would just like to hang out at the beach. I know the weather can vary, and it's going to be colder at the beach so I'm thinking jeans and sweatshirts? Am I on the right track?