Lake St. Moritz — Year comparison & records

The 2026 water level compared to last year and to the 1991-2020 reference period: median, typical range (25th-75th percentile) and the extremes of those 30 years.

Level compared with usual

Very lowNormalVery high

usual range

Low — 7 cm below the median — lower than usual for this calendar day (reference period 1991-2020).

How unusual is this?

Values for this time of year are compared over 1991-2020. The middle 50% lie between 1,767.81 m a.s.l. and 1,767.89 m a.s.l.. Below the 5th-percentile boundary (1,767.73 m a.s.l.) is very low; above the 95th-percentile boundary (1,767.96 m a.s.l.) is very high.

This seasonal assessment uses published quantiles. It is not a return period or forecast and cannot count individual historical years.

Current year 2026
Previous year 2025
Median
25th-75th percentile
Maximum / minimum

How to read the chart: the thick line is the current year, the thin one the median of the 1991-2020 reference period. The shaded band shows the normal range (25th–75th percentile), the dotted lines the maximum and minimum. Values above the band are unusually high for the season, below unusually low – but not an official warning.

What historical readings show

What the year comparison shows for Lake St. Moritz

Typical low point

1,767.81 m a.s.l.

April 13

Typical high point

1,768.04 m a.s.l.

June 8

Typical range

23 cm

Difference between daily medians

In the 1991-2020 reference period, Lake St. Moritz's seasonal median is lowest on April 13 at 1,767.81 m a.s.l. and highest on June 8 at 1,768.04 m a.s.l.. The difference between these typical points is 23 cm. This describes the average seasonal cycle, not the largest individual fluctuation.

The 2026 curve currently contains 311 calendar days. On November 7 it shows 1,767.80 m a.s.l., which is 6 cm below that calendar day's median of 1,767.86 m a.s.l.. Compared with the same calendar day in 2025, the value is 12 cm lower.

For the comparison years 1991-2020, the highest displayed value is 1,768.19 m a.s.l. on November 7 and the lowest is 1,767.28 m a.s.l. on October 29. These extremes apply to this period, not the entire measurement history.

The analysis uses the water-level series from St. Moritzersee, St. Moritz. Matching calendar days are compared, and the median is the middle value of the reference years. This classification does not replace flood warnings or local safety information.

Highest value (1991-2020)1,768.19 m a.s.l.

Lowest value (1991-2020)1,767.28 m a.s.l.

Source: FOEN, 1991-2020 reference period