Dressing for the Azores in 2026 requires the "Onion Strategy"—thin, breathable layers that can be easily added or removed. The islands are famous for having "four seasons in one day" due to their mid-Atlantic location. You should prioritize a high-quality waterproof, breathable rain jacket (Gore-Tex or similar) as sudden mist and showers are common even in summer. For footwear, waterproof hiking boots with good grip are essential for the volcanic trails and muddy caldera paths. Avoid light-colored clothing or expensive swimwear if you plan to visit the iron-rich thermal baths in Furnas, as the minerals will permanently stain fabrics orange. Pack moisture-wicking base layers, a lightweight fleece for breezy evenings, and a sun hat. Even if the forecast looks sunny, the humidity can make 20°C feel much warmer, while the Atlantic winds can make it feel significantly cooler, so versatility is the key to remaining comfortable.