The best time to visit Barcelona is during the spring and autumn seasons when the weather is warm and the city is not too crowded. Spring in Barcelona spans from April to June, while autumn runs from September to November. During these seasons, the average temperature in Barcelona ranges from 15 to 25 degrees Celsius. The mild and pleasant weather makes Barcelona a comfortable destination to explore.

If you want to avoid tourist crowds, you can visit from January to March or from October to December. During these periods, the weather in Barcelona is still relatively warm but less crowded.

Eixample, La Rambla, and areas near Barcelona-El Prat International Airport are popular among tourists for accommodation as they offer a variety of attractions and amenities. Eixample is a modern district known for its beautiful architecture, including the works of Antoni Gaudí. La Rambla, on the other hand, is a bustling street filled with shops, restaurants, and tourist attractions.

Barcelona is renowned for its vibrant culture and it often hosts several exciting festivals each year. For instance, there's the Primavera Sound Festival, an indie and alternative music festival held over two weekends in May, and the La Mercè Street Arts Festival, which showcases street art, dance, and music and takes place every September.

Additonally, there's also the Sitges Carnival, an annual carnival held in the coastal town of Sitges near Barcelona in February or March, and the Nit de Sant Joan festival, a summer celebration throughout Spain on the night of June 23rd, marked by bonfires, fireworks, and music concerts.

Barcelona offers a plethora of enjoyable activities for tourists. First and foremost, you must explore its iconic landmarks, such as Sagrada Familia, Park Güell, and the Gothic Quarter.

Afterward, you can take leisurely strolls and soak in the city's atmosphere on La Rambla, relax on Barceloneta Beach, experience Catalan culture by visiting the Picasso Museum and the Magic Fountain of Montjuïc, or enjoy Barcelona's nightlife in the El Raval and Poble Sec areas.

For culinary delights and shopping, you must try tapas at local restaurants or cafes and shop at the bustling La Boqueria market.

This culinary-rich city offers a wide range of local dishes and drinks that are a must-try while on vacation there. For instance, there's Paella, a typical Spanish rice dish often loaded with seafood. It's so popular you'd regret missing out.

Apart from paella, there's Gazpacho, a cold Spanish soup made from tomatoes, peppers, and cucumbers, and Tapas, savory snacks or appetizers, typically involving bread, meat, seafood, or even vegetables.

For dessert, there's Crema Catalana, a Spanish-style custard dessert similar to crème brûlée, and Cava, a Spanish alcoholic beverage made from grapes.