Weltklasse is the most prestigious one-day athletics meeting in the world, held at the Letzigrund since 1928 and long the final of the Diamond League. More world records have been set at this meeting than at any other outside a championship.
The organisers publish attendance per edition; we have not collected a dated one.
A listings note: MOLT's Swiss calendar carries Weltklasse Zürich twice, under May and under August. There is one meeting. The May entry has no event behind it.
The Letzigrund holds around 26,000 for athletics and sells out; the city's trams run extra services, and the stadium is twenty minutes from the Hauptbahnhof.
PlanningOne evening in late August or early September — not two, and not in May.