Barcelona for the most part has very enjoyable, mild seasons.  It is located right on the coast of the Mediterranean Sea, causing it to have what is considered a "Mediterranean Climate," which would be subtropical.  The city and region experiences mild winters, and very warm and humid summers.

Barcelona, Spain is considered maritime, as it is in a coastal region.

(http://mapsof.net/map/spain-climate-map)

(http://www.mydestination.com/barcelona/6172674/barcelona-weather-forecast)