WeatherChecker is an open source weather reporting tool.
It is used on a number of the Wikinews sites to present a weather map which displays temperatures in Celsius or Fahrenheit for a selection of cities across the world.
Here is a sample weather report generated by WeatherChecker:
The user interface for WeatherChecker is implemented as a multi-panel, C# form window:
The source code for WeatherChecker is available under the GNU General Public License (GPL) and can be downloaded from the WeatherChecker developer site, which is maintained by Wikinews contributor Ilya Haykinson. (Some of the information on the developer site is not up-to-date, so please check on this page for information about the latest features.)