AOL Travel

Barcelona When To Go and Weather

Peak Season September - January; March - July
There’s no “bad” time to go to Barcelona, but the weather is best in May and June and September through November. The generally balmy weather means that something is always happening. The festival season runs about six months long and is book ended by the Diada de Sant Jordi festival in April, which celebrates the patron saint of Barcelona, and the Festes de la Merce at the end of September. Indie rock music lovers flock to Barcelona in May for the Primavera Sound festival and Barcelona is awash in red and yellow on September 11, for the Diada Nacional de Catalunya, which commemorates Catalonia’s struggle for independence.
Off-Season August
If possible, don’t book a trip in August. That’s the month when most locals take off for their summer holidays, and the city becomes a sleepier, slower version of itself, engulfed in unforgiving summer heat. The upside to this time of year is that you might find some discounts at hotels and restaurants.
Shoulder Season February 
Barcelona’s winters are fairly mild, and spring starts early—in February—with the city’s Carnival celebrations. Like most places, March and April can be unpredictable, so if you’re planning on traveling then, make sure to check the local Barcelona weather reports.

Monthly Averages