Norte in September

April through October gives you the best weather, but each season has its personality. Spring (April-May) brings wildflowers to Peneda-Gerês and comfortable temperatures around 18°C, though expect some rain. Summer (June-August) means perfect beach weather and long daylight hours, but also crowds in Porto and higher accommodation prices. September and October offer the sweet spot — warm days around 22°C, fewer tourists, and grape harvest season in the Douro Valley. Winter isn't terrible if you stick to cities, with temperatures around 10-15°C, but mountain areas can be harsh and many rural accommodations close. The São João festival in Porto (June 23-24) brings street parties and plastic hammer fights — book accommodation months ahead. Avoid August if you want to experience authentic local life, as many Portuguese take their holidays then.