Today I found an article on ASP.NET official website introducing a custom control to show weather on your website.

Milan Negovan has talked about his control and features in this article. I know it's two easy to write some lines of code to use a customized RSS feed from Yahoo! Weather (RSS example for Tehran current weather) or other websites and display it in an appropriate format in our websites, but as a ready-to-use tool you can just download this control and drop it in your client projects as an extra feature! Before download you can see a live demo here.

For those who want to challenge more with technical issues: This article describes how to use NOAA Weather WebService to show a customized look weather report.