This is an El Nino year, so yes, more rain than usual. We spent a week at Laguna Beach last March (but first week). I was OK with shorts and long sleeves during the day with walks on the beach (even wore short sleeves a couple of times), as long as I was active. In the evening, you’ll want a jacket in addition to something long-sleeved if you’re walking into town for dinner. As long as we were walking around and it was sunny, I was fine in shorts. We did a hike at Crystal Cove State Park one afternoon, and I was hot! But it was quite a strenuous hike.