So how, and from where, do we get the data we need from the web? There are, in fact, very many sources that will provide us with data for free, and not just weather data. Searching through Google open data just now yielded 728 million results, which should be enough to keep most curious developers amused for some time.
From the large number of open weather data sources, we will select http://openweathermap.org, which provides a large quantity of data for free to registered users. Go to the URL above and perform the following steps:
Create a new account, which is free, requiring only an email address.
Copy the API Key that will be generated once you have created an account.
You're done! Now you have an API key that you will include when you request data from the server, confirming that you are entitled to access that data. The key will look something like this: 78c75588dfe58276a694af9c660edxxx
With less form-filling than it takes to create a Google...