What to wear to La Tomatina: Buñol sits at 32°C (90°F) by day and 20°C (68°F) at night in August, on city streets, with a low chance of rain. That means loose natural fabrics and real sun protection, cushioned trainers or a low boot, and a bag small enough for the gate rules. The crowd leans water, party and costume, so a full costume is the norm rather than the exception.
Men's festival dressing at La Tomatina comes down to three decisions: how much you can take off when it hits 32°C (90°F), what you put back on at 20°C (68°F), and whether your shoes can take city streets for 1 day.
The short version: Old white t-shirt, swim goggles, shoes you are willing to bin.
The dominant aesthetics at La Tomatina are get-soaked practical, party and full costume. That is the visual language of the site, the stages, the merch, the crowd photos, and outfits that speak it look intentional rather than borrowed.
This is a costume festival, and that changes the maths: turning up in normal clothes is the conspicuous choice. Budget for one full look rather than three half-hearted ones, and make sure you can walk, dance and queue in it for eight hours.
What people actually wear: as little fabric as the venue allows, in natural fibres, with a bag small enough to forget about.