Tinyweather is a library that allows to get information about weather from Yahoo.
Example of using:
static void Main(string[] args)
{
Weather weather = new Weather("2123805");
CurrentWeather current = weather.GetCurrentWeather();
List<Forecast> forecast = weather.GetForecast();
Console.WriteLine(current.Humidity.ToString() + " " + current.LastUpdate);
Console.ReadLine();
}