What to wear to Mysteryland: Haarlemmermeer sits at 22°C (72°F) by day and 13°C (55°F) at night in August, 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 rave, edm and costume, so a full costume is the norm rather than the exception.










