What historical readings show
What the year comparison shows for Lake Joux
Typical low point
1,003.24 m a.s.l.
February 26
Typical high point
1,004.50 m a.s.l.
May 23
Typical range
127 cm
Difference between daily medians
In the 1991-2020 reference period, Lake Joux's seasonal median is lowest on February 26 at 1,003.24 m a.s.l. and highest on May 23 at 1,004.50 m a.s.l.. The difference between these typical points is 127 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 1,002.74 m a.s.l., which is 163 cm below that calendar day's median of 1,004.37 m a.s.l.. Compared with the same calendar day in 2025, the value is 175 cm lower.
For the comparison years 1991-2020, the highest displayed value is 1,005.28 m a.s.l. on January 15 and the lowest is 1,001.95 m a.s.l. on March 19. These extremes apply to this period, not the entire measurement history.
The analysis uses the water-level series from Lac de Joux, Le Pont. 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.