In terms of precipitation, rainfall in Barcelona ranges from 0.8 - 3.6 inches per month. October is typically the wettest month, when rainfall can reach 3.6 in. July is typically the driest time to visit Barcelona when rainfall is around 0.8 in.
If weather is an important factor for your trip to Barcelona, use this chart to help with planning. For those seeking warmer temperatures, August is the ideal time of year to visit, when temperatures reach an average of 75.2 F. Travelers looking to avoid the cold should look outside of January, when temperatures are typically at their lowest (around 48.2 F).