São João belongs to a much older midsummer tradition. Porto’s municipal cultural organisation traces the celebration to the 14th century and to solstice customs associated with harvests and abundance, later folded into the feast of Saint John the Baptist. Its history is measured in centuries rather than a single modern launch date.

That mixture of sacred and everyday traditions still shapes the night of 23 June. Leek flowers, pots of basil and miniature neighbourhood scenes sit alongside street dances, grilled sardines and playful toy hammers. Fireworks over the Douro are the grand finale, but the festival’s character comes just as much from people gathering in their own streets and greeting strangers as part of the same celebration.