Lisbon hosts 2 festivals in this guide: NOS Alive, MEO Kalorama.
Lisbon has 2 festivals in this guide. They run in July and August, and festival-day temperatures range from 28°C (82°F) to 29°C (84°F), with nights down to 19°C (66°F). That range is the reason there is no single "Lisbon festival outfit". The answer changes by month and by site.
Every one of them run in real heat (28°C or more), where loose natural fabrics beat coverage and a brimmed hat does more than any garment.
The ground matters as much as the sky. You will find city streets and city park, which puts broken-in trainers or a low boot at the top of the list for most of these events. 1 of the 2 has camping on site, so outfits have to survive living in a bag on the ground for several days.
Stylistically the crowd here leans indie, streetwear, alt and beach. NOS Alive is the largest of them at around 55,000 people, and it sets the tone the smaller ones react to. None of that is a dress code. It is what you will see, which is worth knowing if you would rather blend in or deliberately not.
