This is a POC to quickly format the data provided by http://om.yr.no/ using the XSLT transformation provided by modern browsers.
Be careful to respect the terms of use : http://om.yr.no/verdata/free-weather-data/
The example forecast data can be found here : http://www.yr.no/place/France/Poitou-Charentes/La_Rochelle/forecast.xml
Find your XML URL at http://fil.nrk.no/yr/viktigestader/verda.txt