Barcelona's weather makes it a great destination for year-round visiting. The summers are warm and reasonably dry and the winters and mild and humid. It is only during August, when the locals flee the city because of the heat, humidity and accompanying storms, that Barcelona becomes a little uncomfortable. Summer lasts nearly six months with average temperatures between 20°C and 25°C, pushing close to 30°C in August. Winter temperatures hover around 10°C and it is rare for conditions to be freezing. Barcelona's rainfall is fairly evenly spread throughout the year but is never enough to deter a sightseeing trip.
April to July and September are when Barcelona receives the most visitors, with tourists taking advantage of the warm weather. We also think that March, October and November are lovely months to visit, but considering the mild climate in Barcelona it's possible to visit any time of year without any inconvenience. If you're looking for a cheap holiday to Barcelona, prices for flights and accommodation are at their lowest in January. Visitors braving the hot month of August will find the city pretty empty, but with that comes widespread closures of shops and restaurants, as well as some of the attractions, although the major sights normally remain open.