Reference data analysis
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 265 calendar days. On September 22 it shows 1,002.79 m a.s.l., which is 141 cm below that calendar day's median of 1,004.20 m a.s.l.. Compared with the same calendar day in 2025, the value is 122 cm lower.
Within the 1991-2020 reference period, the envelope reaches its highest value of 1,005.28 m a.s.l. on January 15 and its lowest value of 1,001.95 m a.s.l. on March 19. These are extremes of the displayed reference period, not all-time records.
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.