San Diego is one of those destinations that seems practically effortless to visit. While that's partly true, locals know that there are plenty of unwritten rules that can make the difference between a completely smooth experience, and sticking out as a first-time tourist. From understanding why the beach isn't always sunny in June to knowing when it's actually worth planning your vacation, a little local knowledge goes a long way. Whether you're visiting for a weekend getaway or a longer Southern California road trip, these San Diego etiquette tips and insider rules will help you experience the city the way locals do while avoiding some of the most common mistakes visitors make. As someone who has lived in Southern California for over eight years, and has visited San Diego many times, I've pulled from personal experience to compile these unwritten rules, while also referring to locals via Reddit and blogs.