Barcelona is an established city-break destination with a year-round tourist, business and convention trade. Different seasons have different attractions, from summer music festivals to Christmas markets, but there’s always something going on.
As far as the weather is concerned, the best time to visit Barcelona is late spring or early autumn, when the weather is still comfortably warm (around 21–25°C) and walking the streets isn’t a chore. There might be a chill in the air in the evening, but Barcelona in these seasons is sometimes nigh on perfect.
However, in summer the city can be unbearably hot and humid, with temperatures averaging 28°C (but often a lot more). August, especially, is a month to be avoided, since the climate is at its most unwelcoming and many shops, bars and restaurants close as local inhabitants head out of the city in droves.
It’s worth considering a winter break, as long as you don’t mind the prospect of occasional rain. It’s generally still warm enough to sit out at a café, even in December, when the temperature hovers around 13°C.
Out of Barcelona, the weather varies enormously from region to region. On the coast it’s best – naturally enough – in summer, though from June to September tourist resorts like Sitges are packed. Tarragona, too, can be extremely hot and busy in summer, though it’s worth knowing that Girona is considered to have a much more equable summer climate, and escaping from the coast for a few cool days is easy.