First off, let me give you some background information on Lake Zürich: It has an extension of 90 km², a maximum length of 40 km, a width of 2 km and depth of 143 m, being placed at 406 m above sea level.
Incredible as it may sound, this 3900 km³ mass of water can actually freeze over!!! The records show that since 1233, the lake has been frozen 26 times, the last time taking place in 1963.
Especially long lasting was the Seegfrörni of 1891, which lasted from January 21 until March 1 ("Seegfrörni" is Swiss German for "lake freeze"). Can you imagine!? That year on February 15, about 6000 people walked on the frozen waters of the lake, which reached a thickness of 27 cm/10.5 in.
The night of February 18, 1961, the lake was light up with Chinese lanterns and bonfires to commemorate the magic event.
During the most recent lake freeze in 1963, the city of Zürich even organized a fair which lasted for 30 days!
(Picture copyright by Daniel Sieber)
And the most incredible discovery recorded during these cold periods was a 57 cm thick piece of ice with a frozen fish inside! Did you know temperatures need to remain below -10 C for more than 40 days in a row so that this phenomenon can occur?!? That's cold!
(All other pictures copyright by Peter Märki)
If you find any more pictures or you know someone who experienced a lake freeze, please let us know!