What historical readings show
What the year comparison shows for Lake Geneva
Typical low point
371.66 m a.s.l.
April 21
Typical high point
372.24 m a.s.l.
July 7
Typical range
58 cm
Difference between daily medians
In the 1991-2020 reference period, Lake Geneva's seasonal median is lowest on April 21 at 371.66 m a.s.l. and highest on July 7 at 372.24 m a.s.l.. The difference between these typical points is 58 cm. This describes the average seasonal cycle, not the largest individual fluctuation.
The 2026 curve currently contains 310 calendar days. On November 6 it shows 372.16 m a.s.l., which is 4 cm below that calendar day's median of 372.20 m a.s.l.. Compared with the same calendar day in 2025, the value is 10 cm lower.
For the comparison years 1991-2020, the highest displayed value is 372.51 m a.s.l. on July 29 and the lowest is 371.32 m a.s.l. on April 23. These extremes apply to this period, not the entire measurement history.
The analysis uses the water-level series from Genève-Sécheron. 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.