What to wear to Field Day: London sits at 23°C (73°F) by day and 15°C (59°F) at night in August, on city park, with a moderate chance of rain. That means a light base with one warm layer you can carry, cushioned trainers or a low boot, and a bag small enough for the gate rules. The crowd leans techno, underground and streetwear, so black and functional reads as insider.
Men's festival dressing at Field Day comes down to three decisions: how much you can take off when it hits 23°C (73°F), what you put back on at 15°C (59°F), and whether your shoes can take city park for 2 days.
The dominant aesthetics at Field Day are techno black, underground, streetwear and urban. 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 function-first crowd. Black, utility and good shoes read as insider; heavy glitter and fancy dress read as tourist. Nobody is stopping you, but you will feel it.
What people actually wear: one good layer over a light base, because the temperature halves after sunset.