Seasonal level comparison

Lake levels compared with the seasonal normal

Each lake is compared with its own long-term median for today’s calendar date, showing where levels are currently higher or lower than is typical for the season.

lakes above the seasonal median

lakes below the seasonal median

lakes virtually at the median

Deviations in centimetres

Every value is relative to that particular lake. A deviation of +10 cm means its current level is 10 cm above its seasonal median, not above a common Swiss reference level.

Updated: Aug 14, 2026, 4:20 PM

Above the seasonal median

Below the seasonal median

What does seasonal normal mean?

We compare the latest main-gauge reading with the long-term median for the same calendar date. This median is the middle reference value of the historical daily readings and reflects the typical annual cycle better than one fixed normal level.

Reference period of the available FOEN daily statistics: 1991-2020. Reading, timestamp and source are shown for every lake.

This classification is not a flood warning. Only information from the responsible authorities is binding for danger levels and official warnings.

View level movements over the last 24 hours →