Interlaken works year-round but feels like two different places depending on the season. Summer (June through September) is peak time for hiking, paragliding and lake activities; winter (December through March) is for skiing in the Jungfrau region.
The William Tell Open Air Theatre Festival runs from mid-June through September, with nearly 200 performers staging shows Thursday through Sunday. The three-day Greenfield music festival in mid-June draws international bands, and a festival pass includes train travel and camping. The Jungfrau Music Festival follows in early July.
Swiss National Day on August 1 brings parades, fireworks and bonfires. The Jungfrau Marathon in early September covers 26 miles with 1,800 metres of altitude gain and has been called the world's most beautiful marathon.
In winter, the Harder Potschete festival in January features a masked parade from the Market Square, honouring the tradition of mountain spirits. The Interlaken Classics Music Festival in March and April showcases young local talent and is considered the town's most important music event.