Packing for São Miguel in the Azores in 2026 requires the "onion strategy" because the island is famous for experiencing "four seasons in one day." The sub-tropical climate is humid and unpredictable, so layered clothing is essential. Your most important item is a high-quality, packable rain jacket that is waterproof rather than just water-resistant, as horizontal rain and wind are common even on sunny days. For footwear, bring sturdy, waterproof hiking boots with good tread if you plan to visit the iconic crater lakes like Sete Cidades or Furnas, as the volcanic trails are often muddy and slippery. For exploring the capital, Ponta Delgada, comfortable sneakers and smart-casual layers are perfect. You must also pack a dark-colored swimsuit (or one you don't mind staining), as the iron-rich geothermal hot springs at Caldeira Velha and Terra Nostra Park can permanently turn light-colored fabrics yellow. Finally, don't forget a reusable water bottle and a sunhat; the Atlantic sun is powerful when the clouds break, and staying hydrated while chasing waterfalls across this "Green Island" is the best way to enjoy your Azorean adventure.