Reference data analysis
What the year comparison shows for Lake Zurich
Typical low point
405.68 m a.s.l.
February 26
Typical high point
406.03 m a.s.l.
June 19
Typical range
35 cm
Difference between daily medians
In the 1991-2020 reference period, Lake Zurich's seasonal median is lowest on February 26 at 405.68 m a.s.l. and highest on June 19 at 406.03 m a.s.l.. The difference between these typical points is 35 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 405.37 m a.s.l., which is 63 cm below that calendar day's median of 406.00 m a.s.l.. Compared with the same calendar day in 2025, the value is 63 cm lower.
Within the 1991-2020 reference period, the envelope reaches its highest value of 406.99 m a.s.l. on May 23 and its lowest value of 405.59 m a.s.l. on March 4. These are extremes of the displayed reference period, not all-time records.
The analysis uses the water-level series from Zürich. 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.