Seepegel

Lake SempachWater level today

503.36m a.s.l.

-1 cm since yesterday

Measured26 minutes ago

Sempachersee, Sempach · Bundesamt für Umwelt (BAFU)

Change across the visible readings

-1 cm

09/22 – 09/23

Explore readings with your finger or mouse. Arrow keys also work in the chart.

View water balance →Year comparison →Temperature profile →
Share

What would you like to share?

Share on WhatsAppDownload image

For an Instagram story: save the image, then upload it in Instagram.

Year comparison & records

View details →
  • 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.

Today at the lake

The current picture

A factual data summary – not a safety or swimming clearance.

Water temperature

21.1 °C

Pleasant

Modelled

Wind

2.9 km/h

Calm

Measured

Precipitation, 24h

0.0 mm

Dry

Measured

What's happening?

The level has been falling for a week.

-0.03 m ü. M. · over 7 days

Weather at the lake

12.2°Air temperature
0.0mmRain, last 24 h
2.9km/hWind
12.2–12.2°Day range

0.0 mm in 48 h · 0.0 mm over 7 days · Gusts 8.6 km/h · 72 % humidity

Source: MeteoSwiss, station Egolzwil · 2 hours ago

UV index

Low
0Daily maximum 3
Course of the day
69121518

No protection needed.

Source: Open-Meteo

Recent events

7 hours ago

↓Suhre, Oberkirch (outflow): reading fell by 0.0 m³/s

16 hours ago

Modelled lake temperature (1 m depth): new weekly low (20.8 °C)

19 hours ago

Modelled lake temperature (1 m depth): new weekly low (20.9 °C)

22 hours ago

Modelled lake temperature (1 m depth): new weekly low (21.0 °C)

yesterday

Modelled lake temperature (1 m depth): new weekly low (21.1 °C)

yesterday

Sempachersee, Sempach: new weekly low (503.36 m a.s.l.)

Stations

4 monitoring stations
Show monitoring stations
Modelled lake temperature (1 m depth) · CH21.1 °C2 hours ago↓Sempachersee, Sempach · CH503.36 m a.s.l.26 minutes ago→Suhre, Oberkirch (outflow) · CH0.0 m³/s1 hour ago→Suhre, Oberkirch (outflow) · CH503.13 m a.s.l.26 minutes ago→

Webcams at Lake Sempach

Drag the timeline to compare the daily archive images.

Eich › West: Sempachersee

Eich › West: Sempachersee

Archive imageSep 23, 2026, 4:00 PM
Time travelSep 23, 2026, 4:00 PM
09/13Latest image
View original webcam

Understanding the water level

What is the water level of Lake Sempach? See the latest available level, its measurement time and source. Compare readings from the same station to understand the trend.

Reading in context

Putting Lake Sempach's current level in context

The main station at Sempachersee, Sempach reports a water level of 503.36 m a.s.l. at Sep 24, 2026, 1:10 AM. The series is provided by Bundesamt für Umwelt (BAFU). This value is the elevation of the water surface above the official height datum, not the water depth at the shore.

The median for the same calendar day is 503.68 m a.s.l.; the current value is 32 cm below it. The 503.56–503.78 m a.s.l. band contains the middle 50 percent of reference values from 1991-2020. Being outside it is less usual, but is not in itself a hazard level.

Comparison with the nearest valid readings gives -1 cm over 24 hours and -3 cm over seven days. These are net changes between two points in time; they prove neither a continuous rise or fall nor its cause.

Understanding Lake Sempach

Lake Sempach lies in the canton of Lucerne between Sempach and Sursee.

This overview includes 4 monitoring stations for water level, discharge, and water temperature. Not every station provides every measurement. Track changes at the same station, checking the timestamp, unit and source notes.

The curve shows recent level changes. A seasonal median, where available, compares the same time of year. Water can rise while remaining below that median: trend and comparison answer different questions. Neither replaces an official warning.

Measurement quality and sources

Data status

  • Measured — Recorded directly at a monitoring station.
  • Modelled — Computed by a scientific model (e.g. lake temperature from Alplakes), not measured on site.
  • Calculated — Derived from existing measurements, e.g. a balance or a change.
  • Archive image — Last archived image, not live.
Embed codeTag GL6IylOsYou can adjust the width and height if needed.
<iframe src="https://seepegel.ch/embed/sempachersee?lang=en&fields=level%2Cwatertemp%2Cweather&stations=sempachersee-sempach&ref=GL6IylOs" width="830" height="168" style="border:0" loading="lazy" title="sempachersee – Seepegel"></iframe>
Use a specific tag
The tag is already part of the code above — nothing to do here. Only fill this in if you were given a specific tag. Without a tag the widget shows no readings.