I have used a PowerShell module I wrote a while ago to retrieve weather information from Yahoo.com. Yahoo offers a set of web APIs which are free to use, that will provide weather information for a given location. The location is determined by a "Where On Earth ID", or woeid. Fortunately, there are APIs to get that information as well. All of this is very easy to use with the Invoke-Webrequest cmdlet. The result is an XML document, which takes a little bit of work to parse out.
My module has a command to get a woeid:
Once you know that you can get weather information.
Or more detailed information:
You can even pipe one command to the other.
The cmdlets have complete help but instead of comment based help, I am using a MAML-based XML file. I created the file with an early version of SAPIEN's PowerShell Help Writer.
Because I like to think the module contains some good examples of using Invoke-Webrequest and working with XML documents, I have published the module to Github. I hope you'll give it a try and let me know what you think. At some point I might even publish it to the Microsoft PowerShell Gallery.
Very nice.