The standard answer is September - warm, the harvest is beginning in the Douro, the summer crowds are thinning. It is not wrong. But Porto is genuinely interesting in every season, for different reasons, and the honest answer depends entirely on what you are here for. Here is what each part of the year actually offers. Spring: April and May Porto emerges from its Atlantic winter gradually. By April the light has changed - sharper, longer - and the terraces reopen with a cert