What to wear to Tons of Rock: Oslo sits at 20°C (68°F) by day and 12°C (54°F) at night in June, on open field, with a moderate chance of rain. That means a light base with one warm layer you can carry, broken-in boots or sturdy trainers, and a bag small enough for the gate rules. The crowd leans metal, rock and punk, so anything that survives the day reads as right.
Men's festival dressing at Tons of Rock comes down to three decisions: how much you can take off when it hits 20°C (68°F), what you put back on at 12°C (54°F), and whether your shoes can take open field for 4 days.
The dominant aesthetics at Tons of Rock are metal uniform, rock and punk. 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 uniform crowd: band shirt, black bottoms, boots. The individuality lives in which shirts and which patches, not in the silhouette.
What people actually wear: one good layer over a light base, because the temperature halves after sunset.