The Camino Portugués de la Costa traces Atlantic promenades and fishing towns from Porto toward Galicia, where sea breezes and fronts shape daily conditions. May, June, and September align with longer days, warm afternoons, and broadly open services, while late summer water temperatures peak and mornings remain mild. Expect quick shifts between bright spells and passing showers, cooler feels on exposed waterfronts, and alternating sunny intervals and rain across promenades and inland lanes.