Weather will likely play an important role when you plan your trip to Valongo, but bear in mind that cheaper options are usually available when the weather isn't as good. The hottest months are usually August and July, with an average temperature of 21°C, while the coldest months are January and February, with an average of 11°C. The rainiest months in Valongo are October, December, January and November, with each month seeing an average of 199 mm of rainfall.