OK, well I think I finally got a working version.
In the Plugins section you will find the WeatherCat 2.0 plugin with detailed instructions how to set up WeatherCat and how to set it up on the server.
However:
Make sure that you first go very carefully through the main setup of the template. The database updates is wiki page 5, so you need to complete wiki pages 1-4 before you do this. Downloading just this one file (the plugin) will be totally useless unless the rest of the template is already uploaded to your server, you went through the Main settings and you created the MySQL table - instructions all in the wiki.
I know people often just skim through the wiki, but please make sure you read it and also check the FAQ if you run into problems. And if you have a problem and dont find the answer anywhere, then feel free to ask.
Tom has already confirmed to me it works and helped me with the documentation (thanks Tom), but please, once someone confirms it is working, just let me know here and I will also post about it in the blog etc. I need to make sure it works though.