A really easy thing to install on your media centre, and something that makes a lot of sense is a weather plug in. There are quite a few, however I think the Heatwave plugin is the best we have seen.
You can download the 32 bit version here, or the 64 bit version here.
Run the install file and restart the media centre - it's that easy. You can set your preferred city and list up to 6 others, each showing a four day forecast, current weather information and what to expect in the next 12 hours.
Of course you will need an internet connection.
Syrilion