Xerxes Weather Plugin is a WordPress plugin by Nordvind and ReneNurido that uses the Google API and shows the weather of the current user locaction based on there IP adresse.
The plugin is very easy to use – not settings requierd, you can change the CSS with editor by modifying the weathercss.css
Xerxes Weather Plugin is a modifikation of the Simple Weather Plugin.
Download and info: http://wordpress.org/extend/plugins/xerxes-weather-plugin/