This is the end result of being unhappy with the two Weather Icon sets on Cydia. I wanted a look more like the default UI on my iPod so I took some time and try and make a decent set of icons.
Download
Extract Weather Icon.theme to \Library\Themes on the iPod or iPhone and enable it though Winterboard. You need to download Weather Icon from Cydia in order for this to work as well.
The backgrounds to the preview are not static. They change depending on the time. I just put the backgrounds on them to show what it would look like.