Barcelona enjoys a mild mediterranean climate, with enough days of sun a year, and in summer they end up being enjoyed up to 10 hours of sun a day. The summers can be very hot and humid. During the winter, although it makes some cold, the sunny days they are appreciated to go for a walk and to leave to the surroundings.
The nights can be cold. It doesn't usually rain a lot along the year, but rather it makes it rather concentrated in the time that they denominate "cold drop" and that it can embrace from September to November. Strong sudden showers, and torrential rains that cause floods and other disasters in good part of the city take place.
The average daily minimum and maximum temperatures for Barcelona are: December-March (6-16°C); April-May and October-November (11-21°C); June-September (18-28°C).