What to WearBarcelona combines beach culture, a Mediterranean climate, and a real concentration of significant religious and cultural sites — which means the practical wardrobe here spans a wider range than most European city trips.
For the beach and general tourism, light, breathable summer clothing suits the climate from May through September, with a layer worth keeping handy for evenings, when the sea breeze can cool the Barceloneta waterfront down noticeably from how it felt at midday.
For the Sagrada Família and other churches, shoulders and knees need to be covered — enforced specifically at the Sagrada Família entrance. A scarf or cardigan carried for this purpose is the simplest fix if you’d rather wear beach or light summer clothing the rest of the day.
In the Gothic Quarter, comfortable walking shoes with real grip matter given the cobblestone streets, which turn genuinely slippery when wet. For nightlife — and Barcelona takes nightlife seriously, with most venues not getting going until well past most international norms — smart casual is the standard, and dedicated nightclubs may have their own dress requirements worth checking ahead.