Oslo's big events, and how busy they make the city
Every event here is verified by a person, dated from its own organiser, and set against Oslo's day-by-day crowd forecast — so they can be ranked on one scale. "Major" here means an event we have checked and approved as one of Oslo's biggest, whose days our own forecast reads Busy or Packed — or, for now, sit beyond the forecast window. See the city, day by day →
Calm · Lively · Busy · Packed rank a day against Oslo's own year — not a headcount.
#1 Norwegian Constitution Day (Syttende Mai) →
17 May 2027 — we checked these dates against the organiser's own site
Norwegian Constitution Day is the busiest of Oslo's 3 verified major events — its day is Packed, busier than 99% of Oslo's year.
The 2027 Norwegian Constitution Day in Oslo runs 17 May 2027, confirmed; expect Packed days — busier than 99% of Oslo's year. (Avoid-Crowds, as of 2026-10-15; recomputed nightly.)
#2 Norway Cup →
31 July – 7 August 2027 — we checked these dates against the organiser's own site
Norway Cup ranks #2 of Oslo's 3 verified major events by crowd impact — its busiest day is Packed, busier than 98% of Oslo's year.
The 2027 Norway Cup in Oslo runs 31 Jul – 7 Aug 2027, confirmed; expect Packed days — busier than 98% of Oslo's year. (Avoid-Crowds, as of 2026-10-15; recomputed nightly.)
#3 Tons of Rock →
23–26 June 2027 — we checked these dates against the organiser's own site
Tons of Rock ranks #3 of Oslo's 3 verified major events by crowd impact — its busiest day is Packed, busier than 87% of Oslo's year.
The 2027 Tons of Rock in Oslo runs 23–26 Jun 2027, confirmed; expect Packed days — busier than 87% of Oslo's year. (Avoid-Crowds, as of 2026-10-15; recomputed nightly.)
Oslo Marathon (DNB Oslo Maraton) →
12 September 2026 — this edition has passed
The 2026 Oslo Marathon in Oslo has passed; no future date is known yet. (Avoid-Crowds, as of 2026-10-15; recomputed nightly.)
Not yet rankable — its days sit beyond the current forecast window, so we have no measured footprint to rank it by.
Planning Oslo around these dates? Timed entries and tours matched to the day's forecast
Who writes the city guides · Disclaimer — event dates can change; expected dates are labelled and can move.