Lake Zürich Swimming Season Opens Early After Warmest April on Record

Water temperatures reached 18°C this week — three weeks ahead of the typical season — prompting the city to open its lakeside bathing areas from 1 May.

The city of Zürich has confirmed that its lakeside bathing areas — including the popular Strandbad Tiefenbrunnen and Seebad Utoquai — will open on 1 May this year, three weeks ahead of the usual late-May schedule, after water temperatures in Lake Zürich reached 18°C this week.

MeteoSchweiz confirmed that April 2026 has been the warmest on record for the city, with average temperatures 3.2°C above the long-term mean. While swimmers and café operators have welcomed the early opening, climate scientists warned that the trend reflects a broader and concerning pattern of accelerating warming in Alpine lake systems. Lifeguard staffing has been confirmed for all sites from the opening date.