Cool Stuff
Things you find on the internet...
The Swiss Federal Office for the Environment (FOEN) Hydrology dept monitors the water temp at its gauging stations (http://www.hydrodaten.admin.ch/en/) including the one downstream from Lac Leman. Soneone else is feeding these into pachube as a data feed (https://pachube.com/feeds/43397) which means it's trivial to generate an on demand plot of last weeks water temp:
Syndicated 2012-02-24 08:54:00 (Updated 2012-02-24 10:39:07) from Elwell