It is quite easy to do this. I use the BBC Weather site. You can choose your city even if it is not in the United Kingdom. Once you do this, then there is a button EMBED and you need to copy the code, like the one below:
http://news.bbc.co.uk/weather/forecast/8/Next3DaysEmbed.xhtml?target=_parent" allowTransparency="true" width="306" height="435" frameborder="0"
This is for London. Create a web frame and paste the above. And that is it!
Bill