Visiting local bars in Barcelona is better when you know what the weather holds. These rainfall averages and temperatures can help you choose the best time for bar-hopping. The hottest months are usually June and May, with an average temperature of 28°C, while the coldest months are February and January, with an average of 26°C. The rainiest months in Barcelona are December, January, November and July, with each month seeing an average of 400 mm of rainfall.